While at Debconf11, I have several times during discussions mentioned the issues I believe should be improved in Debian for its desktop to be useful for more people. The use case for this is my parents, which are currently running Kubuntu which solve the issues. I suspect these four missing features are not very hard to implement. After all, they are present in Ubuntu, so if we wanted to do this in Debian we would have a source.

1. Simple GUI based upgrade of packages. When there are new packages available for upgrades, a icon in the KDE status bar indicate this, and clicking on it will activate the simple upgrade tool to handle it. I have no problem guiding both of my parents through the process over the phone. If a kernel reboot is required, this too is indicated by the status bars and the upgrade tool. Last time I checked, nothing with the same features was working in KDE in Debian.
2. Simple handling of missing Firefox browser plugins. When the browser encounter a MIME type it do not currently have a handler for, it will ask the user if the system should search for a package that would add support for this MIME type, and if the user say yes, the APT sources will be searched for packages advertising the MIME type in their control file (visible in the Packages file in the APT archive). If one or more packages are found, it is a simple click of the mouse to add support for the missing mime type. If the package require the user to accept some non-free license, this is explained to the user. The entire process make it more clear to the user why something do not work in the browser, and make the chances higher for the user to blame the web page authors and not the browser for any missing features.
3. Simple handling of missing multimedia codec/format handlers. When the media players encounter a format or codec it is not supporting, a dialog pop up asking the user if the system should search for a package that would add support for it. This happen with things like MP3, Windows Media or H.264. The selection and installation procedure is very similar to the Firefox browser plugin handling. This is as far as I know implemented using a gstreamer hook. The end result is that the user easily get access to the codecs that are present from the APT archives available, while explaining more on why a given format is unsupported by Ubuntu.
4. Better browser handling of some MIME types. When displaying a text/plain file in my Debian browser, it will propose to start emacs to show it. If I remember correctly, when doing the same in Kunbutu it show the file as a text file in the browser. At least I know Opera will show text files within the browser. I much prefer the latter behaviour.

There are other nice features as well, like the simplified suite upgrader, but given that I am the one mostly doing the dist-upgrade, it do not matter much. I really hope we could get these features in place for the next Debian release. It would require the coordinated effort of several maintainers, but would make the end user experience a lot better.

A new maintenance release version 0.9.6 of Rcpp went onto CRAN and into Debian earlier today. This release contains a fix which helps the RppEigen package (mentioned previously on this blog), as well as an addition which permits user-defined finalizers for external pointer objects (following a suggestion on the mailing list). Two new examples where added: a Gibbs sampler illustration (blogged about as well) and a Rcpp-based Fibonacci implementation following a question on StackOverflow. And while that last example is clearly degenerate, the 700+ fold net speedup (as shown in my answer) is still pretty neat. The complete NEWS entry is below; more details are in the ChangeLog file in the package and on the Rcpp Changelog page.

0.9.6   2011-07-26
    o   Added helper traits to facilitate implementation of the RcppEigen
        package: The is_eigen_base traits identifies if a class derives from
        EigenBase using SFINAE; and new dispatch layer was added to wrap() to
        help RcppEigen
    o   XPtr now accepts a second template parameter, which is a function
        taking a pointer to the target class. This allows the developper to
        supply his/her own finalizer. The template parameter has a default
        value which retains the original behaviour (calling delete on the
        pointer)
    o   New example RcppGibbs, extending Sanjog Misra's Rcpp illustration of
        Darren Wilkinson's comparison of MCMC Gibbs Sampler implementations;
        also added short timing on Normal and Gaussian RNG draws between Rcpp
        and GSL as R's rgamma() is seen to significantly slower
    o   New example on recursively computing a Fibonacci number using Rcpp and
        comparing this to R and byte-compiled R for a significant speed gain

Thanks to CRANberries, you can also look at a diff to the previous release 0.9.5. As always, even fuller details are on the Rcpp Changelog page and the Rcpp page which also leads to the downloads, the browseable doxygen docs and zip files of doxygen output for the standard formats. A local directory has source and documentation too. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page

Continuing the shameless self-praise from our ftp-team talk, I'm now pleased to present you on behalf of the entire FTP-Team the following: As you can clearly see, you can see nothing. Yes, nothing! As of 18:55:52 UTC+2 the NEW queue, which at some times was well over 500, sometimes even 600 packages is now empty. Completely empty. To the best of my (and Ganneff's knowledge) the last time the NEW queue was empty was at least five years ago. Interesting enough, that triggered an yet undiscovered bug in dak, which refused to scan an empty directory...

I ve actually spent a few hours searching around for a good backup solution for my mailbox until I decided to stick with getmail. What you ll be able to achieve after reading this HowTo and deploying the following setup is:

1. A full backup of your e-mail DATA in the Mbox format. (yes, Gmail s labels / folders as well)
2. Prevent getmail to mark all mails as read after delivering them. (this was a pretty bad issue since getmail was marking all my mails as read even if I did not access my e-mail at all)
3. Keep your backups up-to-date with the latest content from your mailbox. (by default getmail grabs all the DATA from your mailbox and fills up the Mbox / Maildir content keeping deleted mails. So let s say I deleted a mail two days ago, well it ll still appear on today s backups. This behaviour is definitely unwanted)

I ll now move to explain a few details about my new configuration but before moving to tweak getmail s main config file, please do the following change on _retrieverbases.py* :

return self._getmsgpartbyid(msgid, (RFC822) ) to return self._getmsgpartbyid(msgid, (BODY.PEEK[]) )

When done grab the following getmailrc and adapt it to your needs**:

[retriever]
type = SimpleIMAPSSLRetriever ## or SimplePOP3SSLRetriever.
server = imap.gmail.com ## or pop.gmail.com for POP3.
username = example@gmail.com
password = password ## so-called Gmail s labels should be listed one by one here for getmail to retrieve mail from them successfully. mailboxes = ( INBOX , [Gmail]/Sent mail ,
ubuntu , gnome/example , linux/example ) [destination]
type = Mboxrd
path = ~/.getmail/backup.mbox [options]
delivered_to = false ## No delivered_to header added automatically.
received = false ## No received header added automatically.
verbose = 2 ## getmail will print messages about each of its actions.

When done we should go ahead setting up getmail s directories and config file:

mkdir $HOME/.getmail cp $HOME/getmailrc $HOME/.getmail/ ## Adapt $HOME/getmailrc to whatever dir you put that file into.

But pretty much all the remaining work will be done by a small shell script I wrote:

#!/bin/sh WORKDIR=$HOME/.getmail
date= date +%d-%m-%Y_%H:%M if [ ! -f $WORKDIR/backup.mbox ]
then
touch $WORKDIR/backup.mbox
fi getmail > $WORKDIR/getmail.log
OUT=$?
if [ $OUT -eq 0 ]
then
mkdir -p $WORKDIR/backups/ && mv $WORKDIR/backup.mbox $WORKDIR/backups/backup_$date.mbox ;
else [ $OUT -eq 1 ]
exit 1
fi ## Cleanup older than 3 days backups
find $WORKDIR/backups/* -mtime +3 -exec rm ;
cd $WORKDIR && rm -rf oldmail-* ;

This script will:

1. Run getmail using the getmailrc config file you previously worked on.
2. If the above command will be successful, it ll create a backups dir into $HOME/.getmail and move the latest Mbox file there appending a date and time to its name. (by doing this we are sure next getmail run will happen on an empty backup.mbox file, thus it will just contain the latest content from your mailbox)
3. It ll re-create a backup.mbox file on $HOME/.getmail to avoid the next getmail run to fail.
4. In the end, it ll clean up older than 3 days backups to avoid a too crowded backups folder. (it removes the oldmail file as well since it is useless in our case)

In the end set up a cronjob that will run the above script and generate the backups for you every one hour:

0 * * * * $HOME/.getmail/getmail_run.sh > /dev/null

Feel free to let me know if you ve encountered any issue while following the above HowTo. Enjoy! * /usr/share/getmail4/getmailcore/_retrieverbases.py on line 901. ** More documentation about the getmailrc file and syntax can be found on getmail s documentation page.

If a single man can display so much hatred
think only of how much love we all can display together.

Stine Renate H heim

I wrote a Norwegian post explaining my experience at Ut ya. I had taken this blog for dead, and had entirely forgotten that it was syndicated on Planet Debian. I don t want to let Google Translate make this disaster any worse than it is the translation of bullets into balls being particularly bad so the international attention the massacre has garnered in consideration, I am writing an English translation of my experiences. I feel somehow duty-bound to make people aware of what happened, but I don t want to get into anything else but a sober description of the events and some very brief reflections. There are many details I have chosen to omit. Others have written their experiences of the events at Ut ya. I wanted to write mine down as well, and get it out there . Partly, I want to write this down because I m unsure if I will remember all the details at a later point in time, although I think I d prefer it if I couldn t. I m also writing this because people are asking about my experiences and it s much better to have an URL to give them, lest I have to keep going through the same spiel over and over again. Our former Prime Minister and current labour movement demigod Gro Harlem Brundtland had recently left the island. I had been the cameraman for a video interview of her talking about Ut ya, and I was in the media group room encoding the video into a file suitable for YouTube, when someone else in the room startled and said that Twitter was full of messages about a loud explosion in Oslo. As the newspapers brought us information about the extent of the damages, a consensus arose that an informational meeting was in order. As soon as the current round of talks finished, we were gathered into the main hall. The meeting was duly held, and after the statement was made that a TV feed would be made available, I took it upon myself as the local alpha geek to make it happen. Of course, the situation caused both the wireless network and the GPRS networks to become totally unusable. As I was waiting for someone to set up a password, I took the opportunity to face the consequences of having eaten two bits of a microwavable dish called Hold-It the local equivalent of a Hot Pocket and went to the toilet. As I was in there, I first heard agitated shouting, then screams, then gunshots coming from just outside the toilets. More than anything else, it sounded like a toy gun. I was convinced that someone was making a joke in incredibly bad taste and I stormed out of the booth with the intent of halting it. As I tore the door open, I saw two of my comrades hiding in a recessed corner. Their facial expressions left absolutely no doubt that this was no toy. They signalled for me to get back in the booth. I closed the door, did a mental double-take in utter, complete confusion, and opened it again. They were still signalling. Had they not stood there, I would have run straight into the gunman; they saved my life. I looked out into the hallway, and I made eye contact with a young boy lying in a pool of blood. He was motioning for me to help him. I heard more gunshots from inside the building and retreated back inside. As I was trying to think through my next move, I realized that the decidedly insubstantial wood-fiber door would not resist any kind of bullets. I made my way out into the hallway, with the intent of escaping outside. At that point, I was of course not aware that there was an intention to kill as many as possible, so I thought that the open spaces outside would be a place of relative safety. Of course, this proved to be wrong and my life was probably saved a second time by one of the caf volunteers taking me into a hard-to-spot employee s bathroom. We sat there for ninety minutes. Always ready to make a run for it, ready for just about anything. A peculiar group dynamic arose with these two people with whom I had barely previously spoken. We came to share a strange sense of common destiny and gallows humour. One of them had seen the shooter and described the police uniform. I perceived it to be realistic that we were the only ones aware of the wounded outside the toilet. I tried to reach the emergency services, but all their lines were busy; the terror attack in Oslo had probably clogged their lines. I finally got through to the fire services, who could inform me that the police did know about the situation and were on their way. This was to take 90 minutes and by the time we evacuated, the young boy outside my door had perished. The despair I first saw in his eyes as I passed him, fleeing from one room to the other and the empty, blank stare as we left, are burned into me and they are images I will never in my life forget. Finally, the real police arrived. We walked out. I chose the path through the minor conference hall something I now regret. The sight was simply beyond my capacity to describe fully, and so terrifying that I barely remember the sight only the terror it struck in me. There were several people bunched up in a corner, a big amorphous heap of bodies. Some were conscious and yelled at me not to do anything that could startle the police, others lay still. Their bodies were all covered in blood, and a thick pool of blood extended at least a half-metre in all directions around them. The policeman across the hall was screaming orders at me, but he was screaming so loudly that I couldn t make out his words at first. We were first moved into the camp newspaper s offices. There were about eight of us there, I think, in addition to one girl who lay wounded. Towards the end she was drifting in and out of consciousness. We covered her with sweaters to keep her warm and one of us tried to at least temper her bleeding. The bullet had missed her heart, but by the entry wound it was clear that it was not by far. I do not know who this girl was or how she is now. I sat behind and never saw her face. The wounded were evacuated first. I don t remember how long we remained; I had lost all concept of time. In spite of protests from the group who knew him, one kid was put in handcuffs. At the time I didn t understand why, and the policeman seemed to say something almost to the effect that there was no reason for it at all. I didn t see when they undid his cuffs, but I remember thinking that this treatment made a terrible experience even worse for him. I tried my best to comfort him but knew it would be little help. Later, when things stabilised a little, we were told that he was handcuffed because he had come from an unsecured area. The police was extremely good at carefully explaining what was happening and why; this was a big help and I am grateful for it. Eventually we were moved out into the main corridor of the building, where we joined up into a group of about fifty. Only when I saw the two people who saved my life did any emotion other than mild confusion arise. I broke down shivering in tears in one of their arms. After a few seconds, I came back to my senses and realised that this was not the time. I quickly gathered myself, got the shaking under control, and sat down. We were given some chocolate and soda from the kiosk. I remember making an offhand remark that an inability to find joy in free candy was a sure sign of a bad situation. We all laughed out loud. Gallows humour is a coping mechanism, but in retrospect one almost feels guilty for it. We were shown out in a single file with hands above our heads. I remember an intense concern that someone would slip in the steep, muddy slope and create a misunderstanding. Outside, there were more bodies. Some under improvised covers a tarpaulin from the waffle stand, the deflated bouncy castle but some simply lay there. Everyone I met displayed a courage, a mental discipline and unity of purpose far beyond anything one would ever wish to expect from people this young. Everyone conducted themselves with an attitude that could almost be described as stiff upper lip . Safely across the fjord we were offered blankets. I was asked if I was aware of any injuries, and asked to lift my shirt and show my abdominal region. We were shown into the bus which took us to the hotel used by the survivors and their family. I simply cannot describe in any words the relief I felt when I was able to embrace my living comrades. It was completely unlike anything I had ever felt before in my life. The euphoric feeling was tempered only by the realisation that there would be many I could never see again, comrades whom I had taken great pride in calling my friends, with futures in the service of all mankind, futures I had previously found such great joy in pondering and guessing about. The feeling which continues to upset me the most, is the feeling that so many of my comrades left behind grieving families and friends. Torn away senselessly. I do not know how much more than this relatively sober account of the events on Ut ya I can muster. I would, however, like to offer some reflections. First of all, from the bottom of my heart, I want to thank the police who saved the lives of so many still on the island, the holidaymakers who took aboard swimmers into their boats and the rescue services staffed primarily by volunteers who have spared no effort in trying to soften the blow as much as they can. The opportunity to spend time with those comrades who underwent the same experience as myself has also been an immeasurable aid. I was also so relieved to find my very closest friend among the survivors, which has also been an indescribable help. If I can name a single positive in this tragedy: Had he arrived with his automatic weapon fifteen or twenty minutes prior, he would have arrived during the informational meeting, at a time when the major hall was absolutely jam-packed the death toll would be many times what it ended up being. I am agonisingly aware of the meager comfort this provides to those who have been bereft of their closest, but I do find some solace in this. We cannot sweep under a rug that this was without question! a political attack on the labour movement. But it is thankfully also an attack which has been perceived by everyone as an attack on the Norwegian society, and on a symbol of the wide recruitment to the participatory democracy which lies at our very national soul. I cannot thank the Norwegian people, and indeed the people in other nations who have offered their condolences, enough for their shows of support and shared grief. It really has been a tremendous help to me knowing that so many people feel with us. I also want to thank from the bottom of my heart the rock-steadiness of everyone in both the national and local wings of the Labour Party and Labour Youth in supporting us, and the political milieu in general for their resolute steadfastness saving me from losing yet more that I cherish; our freedoms in a participatory democracy. Our Party has lost many of its very brightest youngsters. Personally I feel an angry spite, a deep restless urge to get the wheels of society going again. I want to show his kind that we will not be broken. We re stronger than that. I will not be frightened into silence and passivity. I want to remember the dead, and honor them by carrying on our common work. I want to end this with a request to everyone who reads this, echoing a statement I read by one of my good friends and comrades: Please, don t let me see any messages of hatred, wishes for the death penalty, anything like that. If anyone should be of the belief that anything will improve by murdering this sad little person, they would be profoundly wrong. All attention now should be plowed into caring for those victims and their relatives who did not share my luck, and not giving an audience to a perpetrator who wants one. Tore Sinding Bekkedal

Oppdatering: Jeg har skrevet en engelsk versjon av dette som er mer gjennomtenkt. I have written an English version of this post which I have had more time to think through. Det var meningen f rst ha dette som en kladd, for senere g igjennom og skrive mer, men WordPress krangler og jeg orker ikke finne ut av det. Derfor publiserer jeg dette n . Jeg har lenge nsket sette opp en ny bloggmotor men har aldri kommet meg til gj re det og dette er definitivt ikke tidspunktet, s jeg gjenoppliver min gamle, engelskspr klige blogg. Andre har skrevet sine fortellinger om hva som skjedde p Ut ya. Jeg ville gjerne skrive ned min ogs , f den ut. Jeg vil dels skrive det ned fordi jeg ikke vet om jeg vil huske alle disse detaljene senere. P en m te h per jeg ikke det. Dels ogs for at jeg skal slippe m tte beskrive dette hele tiden for alle som sp r. Gro Harlem Brundtland hadde nylig forlatt leiren. Jeg hadde tatt opp en videohilsen fra henne, og var i kontoret til mediegruppen for redigere filen til noe vi kunne laste opp p YouTube. En av de som var i rommet skvatt til og fortalte at Twitter var fullt av meldinger om en eksplosjon i Oslo. Etterhvert som pressen kunne fortelle om hvor angrepet hadde skjedd, ble det mer og mer tydelig at et informasjonsm te var p sin plass. Det ble enighet om at det m tet skulle avholdes etter at bolken med innledninger var ferdig. Informasjonsm tet ble avholdt, og jeg tok p meg som den lokale nerd-in-chief sette opp en laptop som kunne vise NRK Nett-TV s folk kunne f sett hva som skjedde. Det tr dl se nettverket gikk nesten umiddelbart ned, s vi ble enige om at det skulle settes et passord p det. I p vente av at noen andre gjorde det, gikk jeg p do. Idet jeg satt der, h rte jeg f rst agitert roping, s skriking, s skudd. Det h rtes mer ut som en lekepistol enn noe annet og jeg antok at dette bare var en eller annen som kom med en totalt smakl s vits. Med dette i tankene, kom jeg n rmest stormende ut av b sen men idet jeg vrengte opp d ren s jeg to mennesker som signaliserte at jeg skulle komme meg inn igjen. Ansiktsuttrykkene deres levnet overhodet ingen tvil om at dette var alvor. At de var der reddet utvilsomt livet mitt. Jeg var mest av alt forvirret. Jeg antok der og da det var en AUFer som hadde gjort dette, g tt amok. Jeg tittet ut igjen. De to var der fremdeles. Denne gangen s jeg en person som l der p gulvet, i en blodp l. Jeg hadde yekontakt med ham, og han signaliserte tydelig etter hjelp. Jeg tenkte umiddelbart at de d rene ikke ville st imot noen som helst type kuler, s jeg tenkte kun p forflytte meg vekk fra b sen. Min f rste tanke var komme meg utend rs. Jeg l p ut korridoren, og akkurat da kom en fra kaf gjengen mot meg. Hun pnet ansatt-toalettet, og jeg, hun, og en annen kastet seg inn. Det er bare en av de mange tilfeldighetene som jeg i etterkant m innse at jeg antar reddet livet mitt. Vi satt der, i halvannen time. Klare til l pe, klare for egentlig hva som helst. Det ble til en eiendommelig dynamikk mellom oss tre, en slags perpleks galgenhumor. Jeg, ettersom det var helt realistisk at v r gruppe var den eneste som visste om likene i bygget, pr vde umiddelbart f varslet om det. 112 fungerte ikke. 110 fungerte ikke. Til slutt kom jeg igjennom p 113, og de kunne opplyse om at politiet var klar over situasjonen og var p vei. Det skulle ta halvannen time, og da vi ble evakuert l han der d d. Det ekte politiet ankom omsider. Vi gikk ut. Jeg tok veien rundt lillesalen, noe jeg i etterkant angrer p ; det jeg s der vil nok bli med meg en stund. Det l en haug med folk jeg husker ingen ansikter, bare et stort, amorft sammensurium av kropper i en fryktelig stor blodp l noen av dem, jeg mener huske to, var fremdeles bevisste. Vi ble f rst flyttet til Planet Ut ya-kontoret leiravisa hvor det var en jente som hadde blitt skutt. Vi rev opp noen poser med gensere fra lageret og dekket til henne. Der satt vi en stund jeg hadde forlengst mistet tidsbegrepet jeg mener det m ha v rt tolv av oss. En av ungdommene ble trass i protester fra de i gruppa som kjente og gikk god for ham p f rt h ndjern. Jeg forstod ikke helt hvorfor. Senere ble vi forklart at det var fordi han hadde kommet fra et omr de politiet ikke hadde oversikt over. Jeg s ikke n r de h ndjernene ble l snet, men jeg husker ihvertfall at det slo meg som uverdig behandling. Politimannen som hadde vakt p posten der vi var, var veldig dyktig til forklare oss situasjonen. Vi ble flyttet ut til hovedkorridoren, hvor omkring 50 av oss var. F rst idet jeg s og omfavnet de som antakeligvis reddet livet mitt, knakk jeg sammen i gr t. Jeg tok meg fort inn igjen, fikk skjelvingen under kontroll, og etter en del venting ble vi marsjert med hendene p hodet mot fergen. Jeg husker hvor redd jeg var for at noen skulle gli i den bratte, gj rmete bakken og skape en misforst else. Det var flere lik ute. Noen var tildekket p improvisert vis, andre l der bare. Alle jeg s viste mot, ro og beherskelse p et niv langt over det noen nsker forvente fra folk i de aldersgruppene. Det var et samhold og en m lbevissthet som gjorde et inntrykk. Vel over fjorden ble vi tilbudt tepper. Jeg ble spurt om jeg var skadet, og bedt om vise mageregionen. Vi ble loset ombord i bussen, og kj rt til Sundvolden hotell. F lelsen, den totalt utrolige lettelsen av se sine n rmeste venner igjen kan jeg virkelig ikke beskrive. Lettelsen ble temperert av usikkerheten rundt de man ikke s . Det dreier seg blant annet om mennesker som jeg i skrivende stund m anta har mistet livet. Blant dem mennesker jeg tidligere hadde hatt stor glede av vissheten om at kom til gj re fantastiske ting i landets og verdens tjeneste n er de revet vekk. Jeg vet ikke hvor mye mer enn denne litt n kterne rapport av hendelsene jeg klarer komme med akkurat n . Men slik var det ihvertfall jeg opplevde situasjonen jeg kom ut av takket v re en serie tilfeldigheter. Litt kort vil jeg legge til: Redningstjenestene var en stor hjelp. Vel s stor, om ikke st rre, har muligheten til tilbringe tid sammen med de andre overlevende v rt. Vi holder sammen og tr ster hverandre med v r felles erfaring. Ett lyspunkt ser jeg her: Mest av alt er jeg s utrolig glad for at han ikke var fremme tyve minutter tidligere, under informasjonsm tet. Da var hele Ut ya samlet som sild i t nne i hovedsalen, og med hans automatv pen ville d dstallene i l pet av noen titalls sekunder blitt det mangedobbelte av det vi endte opp med. At det er en veldig mager tr st for de etterlatte er jeg inderlig klar over. Mine aller dypeste tanker er med dem alle. Dette var et angrep p hele det norske demokratiet. I forvirrelsen f ler jeg en bitter trass. Vi skal vise hans likesinnede at det er sterkere enn som s . Jeg vil ikke la meg skremme til taushet og passivitet. Jeg nsker minnes de d de, og deretter hedre dem ved fortsette arbeidet de var en del av.

Earlier this week, Conrad Sanderson issued a minor bug fix release 2.0.2 of his Armadillo library which provides templated C++ code for linear algebra. We wrapped that into a new RcppArmadillo release 0.2.26 and shipped it to CRAN. Due to it being summer and the otherwise tirelesss human operator behind the curtain being on a well-deserved vacation, it sat in the incoming queue til this morning---but is now on CRAN. Conrad did not rest either and just yesterday released version 2.1.91 as a first step towards a new 2.2.0 release sometime soon. And also yesterday, we wrapped that new version into RcppArmadillo release 0.2.27. With CRAN being back in full swing, we pushed it over there this morning and it already made its way into the repository. The NEWS entries summarising the changes---which are exclusively upstream---are below:

0.2.27  2011-07-22
    o   Upgraded to Armadillo release 2.1.91 "v2.2 beta 1"
          * faster multiplication of small matrices
          * faster trans()
          * faster handling of submatrices by norm()
          * added economical singular value decomposition: svd_thin()
          * added circ_toeplitz()
          * added .is_colvec() & .is_rowvec()
0.2.26  2011-07-17
    o   Upgraded to Armadillo release 2.0.2 
          * fix for handling of conjugate transpose by as_scalar()
          * fix for handling of aliasing by diagmat()
          * fix for handling of empty matrices by symmatu()/symmatl()

Courtesy of CRANberries, there are also diffstat reports for 0.2.27 relative to 0.2.26 and for 0.2.26 relative to 0.2.25. As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.

There was an interesting issue in D-Bus, related to unicast vs broadcast signals, which led [edit: typo] to a small change in specs and which might be of some interest for D-Bus developers.

Unicast signals are not widely known and probably even less used, but they are possible.
They are useful, for instance, when you need to trigger an action from a single client, among your listeners.

Until some days ago, when a unicast signal was emitted, it was actually received by everyone listening to the signal's interface (unless a strict rule was added, unusual), waking up a number of processes which actually weren't interested in the signal.
Collateral effect, waking up cost apart: those processes might actually consider the signal as they were the actual recipient and take some action upon it. Bad.

Typical rule having this problem is "sender="org.foo,interface=org.bar".
Imagine several clients using this rule to listen to org.foo, but org.foo wanting to send a signal to :1.23 only.
Specifying destination=:1.23 for the signal object didn't really work since no dest=val was specified in the rule, allowing any destination actually matching it and all the listeners to be woken up anyway.

The problem with this situation was fixing the bad behaviour without filter out eavesdroppers, which actually wanted to receive the message even if not for them.

The solution is a sort of "eavesdrop opt-in", as Thiago proposed to add a keyword to DBusMatchRule, "eavesdrop=true false" which defaults to false and with which the listener declares that it really wants to eavesdrop, enabling it to receive messages (including signals) not meant for it (AKA eavesdropping).
Otherwise any message (again, including signals) with a specified destination won't match a filter with no or different destination. Also a rule with a specific destination won't match broadcast messages.


In other words, by default a match rule filter will match only broadcast messages or the ones specifically for you, unless you declare your very nature of eavesdropper by adding "eavesdrop=true" to your filter rule.

This is a behavioural change and consequently means a small amend to the D-Bus spec for 1.5.x.

It also means that if you maintain some code which acts as an eavesdropper, you should fix the code adding "eavesdrop=true" to your filter.
Note that it's only for 1.5.x branch; adding the "eavesdrop" keyword to a filter sent to a 1.4.x bus will fail as the keyword is not recognized.
An example on how to deal with this change keeping compatibility toward 1.4.x (stable branch) and 1.5.x (devel branch) at the same time is shown by this bustle fix. It checks for the feature presence and prepends the keyword if supported.

Martin Michlmayr is a Debian developer since 2000 and I share quite a few things with him, starting with his age and involvement in the quality assurance team. He managed to be elected Debian Project Leader in 2003 and 2004. He s no longer as active as he used to be but his input is always very valuable and he continues to do very interesting things in particular concerning the support of NAS devices. Read on for the details. Raphael: Who are you? Martin: I m Martin Michlmayr. I m 32, originally from Austria, and currently living in the UK. I ve contributed to various free software projects over the years but Debian is without doubt the one I m most passionate about. I joined Debian in 2000 when I was a student. I worked on Debian more or less full time for a few years while I was pretending to study. Later I started a PhD to do research about quality and management aspects of volunteer free software projects. I investigated the release process in several free software projects, in particular looking at time-based releases. After finishing my PhD in 2007, I joined Hewlett-Packard. I m part of HP s Open Source Program Office and work on various free software and open source activities, both internally and within the community. Raphael: How did you start contributing to Debian? Martin: I first used Debian in the days of 0.93R6, some time around the end of 1995. The 0.93R6 release was still based on a.out but I needed an ELF-based system for some application, so I moved to Slackware. I then quickly moved to Red Hat Linux where I stayed for several years. I rediscovered Debian in 2000 and quickly decided to join the project. I cannot recall how I rediscovered Debian but when I did, it was clear to me that Debian was the ideal project for me: I could identify with its philosophy, I liked the volunteer nature of the project, and I found the size and diversity of Debian interesting since a large project offers a lot of different challenges and opportunities. I remember how many new things there were to learn and back then the documentation and other resources for new contributors were nowhere as good as they are today. My application manager, Julian Gilbey, was a great help he was incredibly friendly and passionate about Debian. I also remember meeting up with Peter Palfrader (weasel) for key signing when we were both in the New Maintainer queue. I was incredibly lucky with my New Maintainer process and soon became an official Debian Developer. Because there was a shortage of application managers, my first major contribution in Debian was to become an application manager myself and help other people join the project. Debian is a large project with a long history and a rich culture, so new contributors should expect that it will take some time to become familiar with everything. Fortunately, there are many resources, such as documentation and the debian-mentors list, for new contributors. Another great way to become familiar with the way things are done in Debian is to subscribe to various Debian mailing lists and ideally to read some mailing list archives. It s also a great idea to attend the Debian Conference or other conferences since meeting people in real life is a great way to integrate. I remember attending Debian Conference 1 in Bordeaux where I gave my first public talk. Finally, new contributors should find an area where they can make a unique contribution. Most people in Debian maintain packages but there are so many other ways to contribute. For example, most of my contributions were not technical but were about coordination and other organizational activities. Raphael: What s your biggest achievement within Debian? Martin: I m particularly proud of a number of achievements:

• New Maintainer: I helped a lot of people join Debian. It s great to help someone join the project and then see how they contribute. Of course, some people join Debian and then quickly become inactive or retire you never know in advance how it will work out. But I had the pleasure to help some truly outstanding contributors to join Debian.
• Quality Assurance: I helped improve QA processes within Debian. In particular, I realized a few years ago that a lot of packages had maintainers who were inactive and that nobody did anything about it. I started to write to those maintainers to see what could be done. It s hard because you don t know the circumstance of someone they may be inactive because of an illness or for other good reasons so you have to be friendly, but yet persistent. Fortunately, most maintainers I contacted were truly inactive and so they couldn t complain when I took their packages away.
• DPL: I acted as the Debian Project Leader for two years. I m particularly proud of this because Debian is a great project and it was an honour to represent it. I performed important organizational and coordination tasks. I also traveled to a lot of conferences and had the pleasure to meet many Debian Developers as well as users of Debian. It s very motivating to meet users and to hear how they use Debian and how we can further improve it.
• Debian on NAS: Debian is without the doubt the Linux distro with the best support for NAS (Network Attached Storage) devices. I was always impressed by what the OpenWRT folks have done to support wireless routers and wanted to do something similar for Debian. Unfortunately, wireless routers just don t have enough storage for a full distro. But then NAS devices came along and they obviously have enough space since they are meant for storage.

Raphael: Speaking about NAS devices: what exactly are you doing on this topic and how can people help? Martin: There are plenty of instructions on the Internet to install Linux distributions on NAS or various embedded devices by connecting a serial console and then typing in hundreds of commands. What I found is that such instructions significantly limit the user base because they are way too complicated for most users. There are just too many steps that can go wrong. So instead, in Debian, we provide a solution that just works: usually, you download a firmware image for your NAS device from Debian and when you upgrade you get the Debian installer. You connect to the installer via SSH and perform a normal installation. The installer knows about the device and will prepare everything for you automatically for example, it knows if the device has requirements for the partition layout and it will install the kernel where the device expects to find it; unfortunately, NAS devices are not like PCs, so the requirements are different for almost every device and therefore you need special code to support a new device. Finally, there are detailed installation guides and we provide help on our mailing lists. There are a number of technical areas for improvement. The installation could be made even easier, and it would be nice to support new platforms and devices. A bigger problem is that while we ve implemented a great solution for NAS devices, we haven t really extended this work to support other classes of devices. For example, tablets and mobile phones are getting incredibly popular and we don t have a compelling solution for such devices, mostly because of the lack of an appropriate GUI. Raphael: What are your plans for Debian Wheezy? Martin: I ve recently been asked by Stefano Zacchiroli, our current Debian Project Leader, to coordinate the care-taking of Debian finances. Debian, as a volunteer project, relies on donations and in-kind gifts (e.g. hardware) to maintain its infrastructure and to support various development efforts, such as funding sprints and other developer gatherings. Debian s money and other assets are held by affiliate organizations around the world. My responsibility will be to keep track of money and other assets (e.g. hardware and trademarks), work with the DPL to establish procedures related to the use of Debian s assets, and make sure that the procedures are followed. Finally, we want to publish public statements so our donors know how we use their donations to further improve Debian. I just started working on this and this will be my main activity in Debian in the coming months. Raphael: Speaking of money, I plan to run a fundraising to get the Debian book I wrote with Roland Mas translated (cf. http://debian-handbook.info). Is this something Debian should support? Martin: First of all, I should make it clear that I don t decide how Debian spends its money. This is up to the DPL to decide together with the project at a whole. I ll just make sure that procedures are followed and expenses tracked and reported properly. Having said that, in my opinion, it s unlikely that Debian as a project will fund this effort. It would be inconsistent with the position of the project not to fund work directly (only some related expenses, such as travel costs to allow Debian teams to organize face-to-face meetings). Whether Debian should support the fundraising effort by helping to promote it is another question and that s probably not as clear cut. It looks like a worthwhile effort, but on the other hand it would be unfair for authors of other Debian books for Debian to put its weight behind one and there are many other efforts that are worth promoting if you promote one, where do you stop? So while it sounds worthwhile, it s probably better for Debian to stay out of it. But somehow related to this, I sometimes worry about the fact that there are so few paid opportunities around Debian. If you contribute to the Linux kernel for a while, you have an excellent chance to get hired by someone and to work on the kernel full time. The kernel may be an extreme example but there are a lot of projects that have more paid opportunities than Debian, e.g. Mono, GNOME, OpenOffice/LibreOffice and KDE. Obviously, there are some Debian Developers who can spend some time on Debian as part of their job. I know that some Canonical employees contribute to Debian, that support companies like credativ improve Debian as part of their work, and that system administrators fix bugs or package new software as they deploy Debian. But I think this is a minority of contributors and even they don t work full time on Debian. Instead what I see is that a lot of people leave university, get a job and then no longer have time for Debian or people start a family and no longer have time. I can take myself as an example since I don t have nearly as much time as I did in the past when I was a student. I guess there are different ways to deal with this problem one would be to create more paid opportunities around Debian outside the project, another one might be to make it easier for new volunteers to join the project. I don t have the answers to these questions but it s something I wonder about, and I also wonder whether pure volunteer projects can still keep up with projects with a lot of full time contributors. Raphael: What motivates you to continue to contribute year after year? Martin: Debian is a great project with a great mission, goals and people. I contribute to make Debian a better solution and to promote the free software philosophy. Finally, the community around Debian provides a lot of motivation. It s amazing how much I ve learned about other cultures because of my involvement in Debian and how many friends I ve made over the years all around the world. Raphael: Do you have wishes for Debian Wheezy? Martin: Not really. I m pretty happy with the way things are going at the moment. We have made a lot of organizational changes in the last few years from which the project has greatly benefited. I m particularly pleased about the plans to adopt a time-based freeze. Raphael: Is there someone in Debian that you admire for their contributions? Martin: There are many people I admire greatly. I d like to mention Joey Hess because he s a great example to follow. He doesn t get involved in politics, is easy to work with and does great technical work. In fact, he has made not one but several contributions that have completely changed Debian (debconf, debhelper, and debian-installer). Furthermore, Debian has a lot of contributors who have done great work over the years but who are not very vocal about it. People like Colin Watson or Peter Palfrader. Debian has many unique contributors and the list of people I admire is much longer than the few people I just mentioned.

---

Thank you to Martin for the time spent answering my questions. I hope you enjoyed reading his answers as I did. He raised some interesting questions. Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Twitter and Facebook.

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Short version arrival was quite easy, the arrival wiki page is now up-to-date and my photos are uploaded every day to this Flickr set. I had a small problem departing from CDG to Zagreb after scanning my suit twice and complaining that it had too many electronic devices, they had me remove my Nexus S, Nokia N950 and Kindle 3 from the suit pockets and then scanned that all lot again. After that another security guy asked me to open my suitcase and started squishing my Ligo cheese and declaring in a grave voice that it was too soft to be legal . As I kept calm and explained the DebConf cheese party to him, he looked around, put the cheese back in the bag and said ok, ok, off you go . So I still have that softness for the party. I heard an even better anecdote from our next years hosts when they were travelling trough Germany, a border official asked a typical so, what are you here for? question. They answered that they were in transit for an IT conference and gave him the invitation letter. He read the letter, nodded and then said: DebConf, huh? So, who was the author of the Linux kernel? and when after the initial shock they gave the right answer, they were immediately waved trough. Now that s what I call good border security. I met up with the guys in the Zagreb airport caf , which was immediately after exiting the secure zone. We waited for dkg to arrive and get his baggage. The passport check too a couple of minutes, but the baggage claim looked to be taking almost a half an hour. After that was sorted out, we took out some local money in one of the 5 ATMs around and went to the bus. We were waived to just put our bags into the bus luggage space and get on, the driver went around to sell us tickets just before we drove off. It was one of the most comfortable and well air-conditioned buses I have been on in a long time. We were in the Zagreb bus station in less than half an hour. Then a funny part started an old man came up to dkg and immediately asked Are you going to Banja Luka? , and when he said yes, the man started dragging us along to the bus station saying that there is a bus to there that will leave in a couple minutes, but we were in luck, so we should follow him right to the bus. Driven by curiosity, we went on. The man dragged us to the far side of the bus terminal bus stops where there was a minibus with Bosnian number plates, but no official designation as a passenger transit bus and no other passengers. They asked a reasonable 120 kuna for the trip, but they looked very shady to me, so we refused. I think that if we agreed and we were lucky enough that they actually did get us to Banja Luka, the price would have risen along the way, for example using the highway tolls as an excuse. After getting cursed at by the old man and being demanded to buy him a beer for his efforts, we went upstairs to the real bus station where we were told that there were two buses to Banja Luka: one at 15:00 and another at 16:30, but that those two buses arrive in Banja Luka almost at the same time, so we got us tickets for the latter bus and went to a local bar to get some food and drinks. I somehow managed to get sausages in deepfried bread that for some reason cost almost triple of a hamburger and fries that others got, but it sure helped to pass the time and after all those 9 was not a bad price for a good meal. We were a bit surprised by the bus drivers asking us to pay 1 (or 8 kuna) for bags to be put into bus bag storage, especially as we for several minutes could not quite understand what they want of us as neither of them spoke either English, Russian or German. I don t remember when was the last time I crossed a real (i.e. non-Shengen) border in a bus, so getting out of the bus and walking one-by-one to the border official was a new experience. On the other border of two bus drivers collected the passports an then brought them back later, so that was less painful. And by then we were in Bosnia! And of the things that greeted us was a billboard for the casino in Banja Luka Hotel Bosna. By the time we got to Banja Luka, dkg had already made friends with an official from Croatian ministry of regional development that sat behind us on the bus and knew English very well (after living in Canada for some time). The bus station in Banja Luka looked almost abandoned like the bus stopped in the field with only a few taxi drivers and a bunch of buildings some distance away showing that this was indeed part of civilization. The taxi drivers would take you to the venue for 8-10 KM 5 or 50-100 kuna (if their meter is broken and you look to be really ignorant of the exchange rates). If you walk on a bit, there is a bus station with an ATM taking Visa cards and a bit further on a bus stop that will take you to the centre of the city for 1.5 KM. The train station looked fully abandoned when we went there, only a news kiosk was working there. The bus driver reacted well to the name Hotel Bosna and wave toward it when we passed by it. It is hard to miss, especially the blinking Casino sign or the white pillars with black letters Hotel Bosna on top. You just get off at the bus station Central and walk back a couple hundred meters. Then see all you Debian friends drinking in the cool bar and walk around the corner to the main entrance of the hotel to check in. The rooms are looking really great this is the best DebConf location that I have been to (I was not in Argentina). Soft beds with linens changed daily, nice air conditioning, towels (changed daily, if used), good shower, It is lacking in the speed and power of its free WiFi and in some place there is a clear impression that the hotel was built as a top of the line hotel a couple decades ago, but somehow has fallen into a disrepair since. Or it is simply used much more than expected. So far I would say that the DebCamp is running full steam two hacklabs have desks, chairs, power and network connection, one of them even has sufficient air conditioning. The network works great for me so far, at least in the venue. The hotel wireless is barely usable to read a blog post, preferably without photos. The food is being served well and on time. So far for lunch and dinner you walk up to the reception and get a food ticket based on your room number and go to the M level for the food (the M level is between the ground floor, labelled as PR , and first floor) where for breakfast and dinner there is a buffet, but for lunch you sit at a table and they bring you food. Vegetarians should clearly say vegetarian while pointing at themselves to get the special vegetarian option. So far food has been very good, except that that they often run out of popular items, such as fries, in the buffet. You can also ask for beer and other extra drinks with your food, but know that they cost extra up to 2.5KM for a beer, for example.

I m organizing August Penguin, the yearly free software / open source conference in Israel for and by the community. We celebrate the 10th time we re holding this conference. I started going to these conferences just after high school, later I got more and more involved and now this is my 2nd year of being the main organizer (with a few others who provide great help). To celebrate the Linux 20th anniversary and August Penguins 10th anniversary, I thought to print copies of the Linux 20th anniversary T-shirts. I tired to contact the Linux Foundation to coordinate this, but got no response. I m writing this post to ask for help with finding the people who can approve this printing in behalf of the Linux Foundation. For those who can read Hebrew, the conference schedule is available at Hamakor s wiki. The rest are welcome to read the English version (provided by Google translate, so not totally accurate).
Filed under: Israeli Community

I decided to go to DebConf11 by car. Not willing to do this alone, I asked for volunteers to join me in my car trip. One such volunteer showed up, and the car trip happened. Now, since I remembered to push the correct buttons on my dashboard after I completely fueled up the car and checked the tire tension and other things, I am now proud to be able to present you with the following statistics on this trip:

1. Total distance travelled: 1466.8 km
2. Average driving speed: 95.9 km/h [0]
3. Total number of kilometers wasted on 'oh, crap, we forgot something': 10 (approx) [1][2]
4. Total amount of fuel used: 81.3l
5. Average fuel consumption rate: 5.5l/100km [3]
6. Total amount of kilometers spent behind the wheel by Jeremy: 50 (approx)
7. Total amount of kilometers spent behind the wheel by Wouter: the rest.[4]
8. Time of departure: 2011-07-16 21:00
9. Time of departure after point three and making sure we had everything: 2011-07-16 22:00
10. Time of arrival: 2011-07-17 15:15 (approx) [5]
11. Outside temperature at departure: 12 celcius
12. Outside temperature at arrival: 35 celcius
13. Longest (voluntary) break: 1 hour (approx; breakfast, tanking, bathroom visit, watching the sun rise)
14. Longest (involuntary) break: 45 minutes (approx; customs check) [6]
15. Last fueling stop: 4 AM.
16. Amount of kilometers left to go before the car said bleep, you need to tank soon: less than one.
17. Most tense moment: on crossing the slovenia->croatia border, confusing the border police officer ("no, I'm Wouter, that is Jeremy" yes, we both had photo-ID), who then promptly holds on to our documents, asks the car's papers, and tells us to please park over there and wait a moment while he gets us to be handled by guy in a somewhat more military-looking uniform.[7]
18. Biggest "uh-oh" moment: after crossing the croatia->bosnia and herzegovina border, watching the very, very, very, very, very[8] long line of trucks queueing to cross the border. In the other direction. And then realizing that you probably need to go through that very same queue on the way back
19. Largest single toll fee: 15 [9]
20. Last bit of time spent asleep before this trip: the minutes surrounding 2011-07-16 05:00:00 [10]
21. Time wasted writing this blog post when I really should've gone to bed instead: 45 minutes
22. Time now: 21:02:54

But it was fun. And that's all that matters. Those who've shown up at debconf already, or who will arrive soon: see you tomorrow. Those who will arrive later: see you soon. And those who won't arrive: better luck next time, I hope. [0] this includes times when the car isn't moving with the engine running, but not times when the car is turned off, locked, alone and forgotten, in the rain, while those idiots who were supposed to be its drivers were inside having a drink.
[1] Which is surprisingly little. Usually I manage to need more.
[2] Jeremy forgot his^Wa Debian banner. I forgot something, I can't recall what. I decided to bring some CD's to enjoy during the trip, and a 3.5mm audio connection cable which we end up not using
[3] According to the dash. I'm too tired right now to check it. Also see the next two points. [4] This could incorrectly be interpreted as a criticism on Jeremy. It's not his fault that I only told him a day before we left that I have a manual transmission. And in fact, if anything, I'm unhappy with the fact that I even had to hand him the wheel for those 50 km. I would've loved to be able to say "I went all the way from Mechlin to Banja Luka, all by myself".
[5] I forgot to check the clock, to be honest.
[6] What, you think I have a chronometer?
[7] The last four points could really have been written as two. Figuring out which goes with which is left as an exercise to the reader.
[8] very, very, very
[9] 7-day Slovenian road tax vignet
[10] Once I wake up, I hardly ever manage to fall asleep again. Esecially if it's light outside.

In an earlier post, I asked a number of questions, most of which are now answered. Here's a recap: I wrote

I stumbled across some CF Engine-style definitions for puppet in a Debian Administration article (taken originally from puppet's own wiki, which have since been moved/deleted)

Perhaps it was removed with good reason This is a fairly horrid solution to the problem. Phil was the first to suggest investigating Augeas, a neat tool that abstracts away the nasty specifics of parsing the myriad configuration file formats and provides a unified, tree-like interface for adjusting configurations. The interface reminds me of manipulating XML via the DOM. More on Augeas in a later blog post I also wrote

package [foo,bar]: syntax worked fine, but is a little verbose and the package list is awkward to maintain buried inside the puppet syntax. I spent some time trying to see whether I could populate a puppet list based on the contents of a file: then I could list the packages one-per-line in a separate file. I haven't found a way of doing that yet.

I haven't found a more concise way of solving this problem, but as I have grown more familiar with puppet's syntax I have become less bothered by it. I igo suggested pre-processing the puppet configuration, but I'd rather not complicate my provisioning approach (VCS hooks) by attempting that. Finally I wrote

Using my laptop as a second node also exposed some interesting puppet client behaviour. Once I went off-site, the laptop tried to look up puppet on foreign networks (such as my home network). I would have assumed that, once the strong SSL association had been made, the client would try to connect to the FQDN of the server. This probably isn't a serious problem in practice, as we probably won't need to rely on nodes off-site talking to the configuration server, but I hope that the client doesn't trust any host that happens to answer to puppet...

I'm pleased to report that the client is at least this clever: it refused to talk to a local puppetmaster that I setup at home.

This Thursday we ll be running a special IRC session, Behind the scenes with the DebConf team . Details:

• When: 19 UTC on 2011-07-14
• Where: #debian-meeting on irc.debian.org (OFTC)
• Log: http://wiki.debian.org/IRC/debian-meeting (after the session has finished!)

This is an open session aimed at anyone who would like to find out more about how DebConf is organised. Of course, we d love you to get involved in organising it yourself, by helping out at DebConf11 or helping plan future DebConfs, but it s also fine to attend the session just because you are curious!

Nina Paley, author/actor/director/animatrist of the excellent sita sings the blues, blogs about the FSF's double standards when it comes to freedom. To the FSF, Software Should Be Free!!1!, and it is willing to go to great lengths to accomplish that. For example, the FSF will create dracionian requirements on their Hardware endorsement criteria, that will most likely render it unusable, just for the remote possibility that they might convert a single soul to their religion. They will add propaganda to their documentation, and slap on a license that makes it illegal for anyone to modify or remove that propaganda. They will claim to make an update to that license, just to make their friends happy, but then do not make any effort to finish the job. Most of all, the FSF is led by a person who deserves our respect for jumpstarting a movement that has made all this free software even possible, but whose atypical behaviour might be interfering with his message these days. I have stated before that I'm not a member of the FSF, and that 'I have my reasons'. In case you were wondering: the above are my reasons. I can't be a member of, or be supporting of, any organization that uses such double standards in anything. In the case of Debian, it took us a long time to come to the conclusion that the GNU FDL is a non-free license. And though we came to that conclusion through other arguments than "Culture should be free, too" (specifically, the arguments boiled down to "if it's digital, it's software, and software should be free"), I have since come to the conclusion that there is nothing special about 'digital stuff' that should mean it should be more free than 'non-digital stuff'. If I hand you a piece of music on a sheet of paper, why should you not have the right to redistribute and/or modify that, while you should have the exact same right if I were to hand you the exact same paper on a digital medium? That makes no sense. So, in short, I agree with you, Nina: there is no Free Culture movement, and that's a shame; and while it would be nice if the FSF were to take a lead role in guiding such a movement, I find it highly unlikely that they will. The FSF may claim they care about Freedom, that doesn't mean they do; they care about Software Freedom. And while that certainly was an issue thirty years ago, when the FSF was formed, it isn't so much anymore today. There can only be one conclusion: the FSF is obsolete.

I watched the final shuttle launch this morning; for several years I've tried to catch shuttle events, knowing it would soon be over, but before that the shuttle had faded into the background for me as it did for so many of us. It was an impractical rocket to nowhere that we mostly only paid attention to when it blew up. Fourteen years ago today, Debian was flying in space aboard Columbia. According to the press release, it ran on an SSD on an embedded 486 in the lab module, and controlled plant watering, telemetry, and video. At the time, I had just become a Debian developer, and was very impressed to be part of a project that was involved in that. It was early days for Debian, and near the midpoint of the shuttle's thirty years. Now it seems likely that Debian, or its derivatives (or at least Free Software) will easily outlast that thirty year run, but I do wonder to what extent our work will fade into the background (and what interesting ways it will find to explode) over that time span and beyond. We'd say we have better methods than the centralized, committee-driven, top-down, PR-conscious NASA... impressive though it can be at its best. We have dreams just as noble as the ones behind the space program, but also goals that are more adaptable, equally at home flying in space, or emebdded in some pocket-lint laden artifact of a perhaps more contemporary inward turn.

There is always been an ongoing debate about how to assign disk space into multiple partitions. I think that nowadays the best thing to do is to assign about 10G for the root filesystem for every desktop and server system because 10G is a small fraction of the disk space available (even the smallest laptops seem to all have disks larger than 100G nowadays). Even if 10G turns out not to be enough using separate filesystems for /var or /usr provides little benefit now that it s easy to resize the root filesystem with LVM and a separate /usr is known to be broken [1]. In a discussion on a private mailing list there was a suggestion that multiple filesystems should be used for security. DoS Attacks There are some minor security benefits in having multiple filesystems. If a critical program will fail when there is no free disk space then allowing an unprivileged process to use up all the space on that filesystem is a minor security issue, so having unprivileged processes not being permitted to write to important filesystems is a benefit. But most failures of this type are merely DoS attacks which usually aren t a big deal if you can control a local process there are usually lots of other ways of DoSing a system. Links Links have been the cause of many security issues in Unix over the years. Using different filesystems for different tasks can prevent the use of hard links in attacks aimed at exploiting race conditions. But even if you prevent hard links there are similar issues with symbolic links. SE Linux is one of many security improvements for Linux which allow restrictions on the creation of hard links. SE Linux also allows restricting the ability of processes to follow symbolic links, so a privileged process can be denied access to follow a sym-link that was created by an unprivileged process. NFS The subtree_check option in /etc/exports causes the NFS server to verify that file access is in the correct subtree. So if you export only one subdirectory of a filesystem to a given server then hostile code on that server (or on a network device which impersonates that server) can t access other subdirectories. This option is documented as having performance implications and working best for filesystems that are mostly read-only, for this reason it s turned off by default in recent versions of the NFS utilities. So if you want to NFS export /home then it s probably a good idea to have /home be on a separate filesystem to prevent attacks on the root filesystem. But of the systems with significant use of /home (IE anything other than accounts used solely for su - ) most of them have a separate filesystem for /home anyway so this shouldn t be an issue. SE Linux When mounting filesystems with SE Linux there is a context= mount option that allows specifying the context for all files on the filesystem. This can save a small amount of storage space for XATTRs and theoretically improve performance (although the difference is unlikely to show up on benchmarks for anything other than fsck). Generally the context mount option is only used for a filesystem that has a huge number of files with the same context, such as a mail spool that uses Maildir, Cyrus, or any of the other formats that involve one file per message. But again such data is generally stored on a separate filesystem for other reasons anyway. I found one interesting corner case in regard to SE Linux systems mounting files from an NFS server. When an NFS server exports multiple subdirectories of a filesystem mounted on /foo then if one NFS client running SE Linux is to mount two subdirectories of /foo with different contexts then the second mount attempt will give the error an incorrect mount option was specified . This is because as of kernel 2.6.18 by default it s not permitted to mount parts of the same filesystem with different mount options. The option nosharecache allows you to use different mount options, but does apparently permit some undesirable behavior in the case of hard links that cross between the subtrees. Thanks to Eric Paris for the tip about nosharecache. The best example I can think of for which you might want context mount options that differ among files that are used for the same purpose on an NFS mount is a web server which has data files and CGI-BIN scripts. So it seems that a SE Linux web server that mounts it s data over NFS and is at risk of having hard links between the CGI-BIN directory and the data directory is a corner case in which multiple filesystems is required for security. This seems to be a very unlikely case. Conclusion Servers that are deployed in the real world are complex enough that there are always systems with some unusual corner cases demanding configuration choices that aren t expected. There are some real corner cases for SE Linux where multiple filesystems are compelled for security or for a combination of security and best performance. But I wouldn t make a generic recommendation of using lots of filesystems for security. I think that the people who encounter the strange corner cases can usually work out that they need to do something different. So a small number of filesystems seems like a good general aim that doesn t conflict with security.

• [1] http://www.freedesktop.org/wiki/Software/systemd/separate-usr-is-broken

Linear regression models are a major component of every applied researcher's toolbox. Obtaining results more quickly is therefore of central importance, particularly when many such models have to be fit. Common examples in this context are Monte Carlo simulation or bootstrapping. My talks introducing High Performance Computing with R (see e.g. these slides from a five-hour workshop at the ISM in Tokyo) frequently feature an example of how to extend R with dedicated compiled code for linear regressions. Romain and I also frequently use this a motivating examples with our Rcpp package for seamless R and C++ integration. In fact, the examples directory for Rcpp still contains an earlier version of a benchmark for fastLm(), a faster alternative for R's lm() and lm.fit() functions. We have also extended this with the RcppArmadillo package which brings Conrad Sanderson's excellent Armadillo library with templated C++ code for linear algebra to R, as well as a simple integration to the GNU GSL via our RcppGSL package. The Rcpp section on my blog contains several posts about fastLm benchmarks. Doug Bates has been a key Rcpp contributor, helping particularly with the initial Armadillo integration. His research, however, also requires highly performing sparse matrix operations which Armadillo does not yet offer. So Doug has started to explore the Eigen project---a free C++ template math library mainly focused on vectors, matrices, and linear algebra (note that we will refer to the Eigen, Eigen2 and Eigen3 APIs as just 'Eigen' here, focusing on the latest version, Eigen3). Better still, Doug went to work and pretty much single-handedly wrote a new package RcppEigen which integrates the templated C++ library Eigen with R using Rcpp. RcppEigen also provides a fastLm implementation and benchmark script. In fact, it contains a full six different implementations as Doug is keenly interested in rank-revealing decompositions which can guard against ill-conditioned model matrices. Some more background information on this is also available in Doug's article on Least Squares Calculations in R in R News 4(1). Doug's implementation also uses an elegant design. It comprises a base class with common functionality, and six subclasses which specialize accordingly for these six different decompositions approaches:

• a column-pivoting QR,
• a standard QR,
• an LL,
• an LDL,
• an SVD, and
• a standard symmetric one.

On my server, the result of running the included benchmark script lmBenchmark is as follows:

lm benchmark for n = 100000 and p = 40: nrep = 20
     test   relative elapsed user.self sys.self
7     LLt   1.000000   0.918      0.91     0.00
3    LDLt   1.002179   0.920      0.92     0.00
5 SymmEig   3.021786   2.774      2.19     0.57
6      QR   5.136166   4.715      4.24     0.48
2   PivQR   5.303922   4.869      4.27     0.58
8    arma   6.592593   6.052      6.03     0.02
1  lm.fit   9.386710   8.617      7.14     1.45
4     SVD  33.858388  31.082     30.19     0.84
9     GSL 114.972767 105.545    104.79     0.63

From this first set of results, the preferred method may be 'PivQR', the pivoted QR. Strictly-speaking, it is the only one we can compare to lm.fit() which also uses a pivoting scheme. In the case of a degenerated model matrix, all the other methods, including the four fastest approaches, are susceptible to producing incorrect estimates. Doug plans to make SVD and SymmEig rank-revealing too. As for pure speed, the LL and LDL decomposition have almost identical performance, and are clearly faster than the other approaches. Compared to lm.fit(), which is the best one could do with just R, we see an improvement by a factor of eight which is quite impressive (albeit not robust to rank-deficient model matrices). Apart from the SVD, all approaches using Eigen are faster than the one using Armadillo, which itself is still faster than R's lm.fit(). Doug and I were very surprised by the poor performance of the GNU GSL (which also uses SVD) via RcppGSL. Now, Eigen uses its own code for all linear algebra operations, bypassing BLAS and LAPACK libraries. The results above were achieved with the current Atlas package in Ubuntu. If we take advantage of the BLAS / LAPACK plug-in architecture offered on Debian / Ubuntu systems (see the vignette in my gcbd package for more) and use Goto BLAS which provide tuning as well as parallelism on multi-core machines, the results are as follow:

lm benchmark for n = 100000 and p = 40: nrep = 20
     test   relative elapsed user.self sys.self
3    LDLt   1.000000   0.907      0.90     0.00
7     LLt   1.000000   0.907      0.91     0.00
5 SymmEig   2.981257   2.704      2.14     0.56
6      QR   5.004410   4.539      4.03     0.50
8    arma   5.072767   4.601     15.30     3.05
2   PivQR   5.307607   4.814      4.27     0.55
1  lm.fit   8.302095   7.530      9.55    12.25
4     SVD  33.015436  29.945     29.06     0.85
9     GSL 195.413451 177.240    244.64   319.89

We see that the BLAS-using Armadillo approach improves a little and moves just slightly ahead of the pivoted QR. On the other hand, lm.fit(), which also uses a pivoting scheme and hence only level 1 BLAS operations, changes less. GSL performs even worse (and it is unclear why). Doug's post announcing RcppEigen on the Eigen list has a few more sets of results. This post has illustrated some of the performance gains that can be obtained from using Eigen via RcppEigen. When not using rank-revealing methods, computing time can be reduced by up to eight times relative to lm.fit(). Rank-revealing method can still improve by almost a factor of two. The main disadvantage of Eigen may be one of the reasons behind its impressive performance: its heavily templated code does not use BLAS, and the resulting object code (as e.g. in RcppEigen) becomes enormous (when compiling with debugging symbols). As one illustration, the shared library for RcppEigen on my Ubuntu 64-bit system has a size of 24.6 mb whereas RcppArmadillo comes in at a mere 0.78 mb; without debugging symbols it is a more reasonable 0.52 mb. The performance of Eigen is certainly intriguiging, and its API is rather complete. It seems safe to say that we may see more R projects going to make use of Eigen thanks to the RcppEigen wrapper.

Update: Clarified statement about large object size which was entirely due to building with debugging support.

It s not very often that I watch a movie anymore. It s been a few years since I ve actually purchased one (normally I see them from Netflix). But yesterday I saw one that may change that. The Lives of Others is an incredible film set in the former East Germany (GDR/DDR) mostly in 1984. The authenticity of it is incredible and so is the story. It s subtitled, but if you re an American wary of subtitled European films, don t be wary of this one. It is easy to watch and worth every minute. The story revolves around the Stasi, the GDR Ministry for State Security ( secret police ). It is an incredible picture of what living in a police state was like, and how many of the informants were victims of the regime too. My breath caught near the beginning of the film, showing the inside of a Stasi building. A prisoner was being interrogated for helping someone attempt to escape to the west. But the reason my breath caught was this incredible feeling of I was there . Last year, Terah and I were in Leipzig and visited the Stasi museum there, Museum in der Runden Ecke . I always have an incredible sense of history when being in a preserved place, and this building was literally the Stasi headquarters for Leipzig. Much of it was preserved intact, and seeing it in the film brought home even more vividly the terrible things that happened in that building, and others like it, not so very long ago. We watched the special features on the Blu-Ray disc, and one of them was an interview with director Florian Henckel von Donnersmarck. He described how he spent a lot of time interviewing both victims of the Stasi, as well as ex-Stasi officers. One of the most disturbing things to me was his almost offhand comment that most of the former Stasi officers still had some pride in performing their jobs well. Even now, freed of the state s ideology, they were proud of the work they did which could be put most charitably as ruining people s lives. What leads a person to view life that way? How can we try to make sure it doesn t happen again elsewhere? I am happy to say that most of us have never experienced anything like the Stasi. And yet, small reflections of that mindset can be seen almost everywhere. Societies at wartime or feeling under threat, even Western democracies, can drum up those feelings. In the USA, for instance, the McCarthyism era saw people s careers ruined for alleged anti-state behavior. Contemporary examples include the indefinite detention (I hate that word; shouldn t we say imprisonment ?) of terrorism suspects at Guantanamo Bay, and the terrible treatment of Bradley Manning, who revealed some true but embarrassing things about the US military which really needed to be revealed. Even tobacco farmers and companies are selling a product they know ruins lives, but somehow keep doing it. And there are still members of the public that try to make life difficult for people that don t think like they do. From organizing campaigns of telephone harassment of colleges that don t perform the American national anthem before sporting events, to tossing about the term un-American (a loaded McCarthyist one, which many may not even be aware) at an inflated rate, we are not immune from attempts at forcing conformity or silence in others, and blind loyalty to state. I am never in a particularly celebratory mood on July 4, the biggest day for American boasting, faux patriotism, militarism, and general flag-waving. We do have a lot to be proud of and thankful for, but it seems that we celebrate all the wrong things on July 4, and see it as an occasion to proclaim American exceptionalism rather than as one to see how far we ve come and bolster hope for how far we can, and should, yet go. No, I don t think that the land of the free ought to have operated secret prisons in Europe (nor the Europeans to have been complicit in it), or that the American military was defending our freedom 100% of the time they were deployed, or that it is right for governments to mandate daily recitation of an untrue document (the pledge of allegiance) in schools. And yet, I am mindful that I have a lot to be thankful for stability, lack of much internal violent conflict, etc. And this particular day I am happy that a post like this is not something that gets the attention of some government agency and mostly that I will have a handful of angry emails to delete.

This is a rant. I've made it in various forms in various places over the years, and I think it's time to put it somewhere so I can point people at it, and stop repeating myself. Here's the pebble in my shoe: people keep claiming that strncpy is a safer alternative to strcpy. It's not. It's a slower function that is not going to make you significantly safer. The problem with strcpy is that it's somewhat easy to overflow the target array:

char src[] = "hello, world";
char dst[5];
strcpy(dst, src); // Oops.

The suggested alternative with strncpy would be this:

strncpy(dst, src, sizeof(dst));

strncpy gets the size of the destination array as a parameter, and can therefore make sure the string will fit there. Problem solved? Not so much. Every time you do any string handling with C's native string types and functions, you need to make sure you have allocated enough memory for each string, you need to keep track of how much memory you've allocated, and you neet to make sure the zero byte ('NUL', '\0') is put there correctly. This is a lot of details to keep track of, and it's not surprising things sometimes go wrong. If your arrays are allocated statically, which is the simplest, but least useful case, you need to something like this with strcpy:

if (strlen(src) + 1 > sizeof(dst))
    panic(); // or however you want to handle your errors
strcpy(dst, src);

The +1 after strlen is to make room for the zero byte (NUL, '\0') that is used in C to indicate the end of a string. With strncpy, your code is slightly simpler. This is its attraction. Problem is, this only works if dst is an array defined within the scope of the code. If, as is common, you have received dst as an argument to a function, sizeof(dst) is the size of a pointer to an element of the array, not the size of the array. So now you need to track the size explicitly in a second variable:

strncpy(dst, src, dst_size);

Further, strncpy has an unfortunate error handling mode: it merely fills the destination array and stops. It does not indicate failure in any way. It does not terminate the target array with a zero byte. Since all C string processing assume the zero byte is there, as soon as you try to use dst as a string, you're in trouble. But luckily you can check for that before you call strncpy:

if (strlen(src) + 1 > dst_size)
    panic(); // or whatever
strncpy(dst, src, dst_size);

By this time, the code is equally hard whether you use strcpy or strncpy. With strncpy you often waste some extra time, though, filling the unused parts of the target array with zero bytes: they're almost never necessary. Alternatively, you can force the zero byte there yourself, silently truncating a string.

strncpy(dst, src, dst_size);
dst[dst_size - 1] = '\0'; // let's hope dst_size > 0

If your string handling is OK with strings being randomly shorter than they should be, possibly you could replace all of them with empty strings, and save yourself a world of pain. Instead of strncpy, use snprintf. It has sensible error behavior, and is much more versatile:

n = snprintf(dst, dst_size, "%s", src);
if (n >= dst_size)
    panic();

snprintf still isn't very nice to use. It still requires you to allocate memory yourself, and keep track of the size of each array manually. It's also slower for small destination buffers (but faster for large ones). The real solution is to abandon C's antiquated string handling, and use a more sensible helper library instead. There's a bunch of them around, though none have gained much popularity. I'm not going to name any of them, but just imagine how much nicer it would be to write code like this instead:

Dynstr *src = dynstr_new_from_cstring("hello, world\n");
Dynstr *cat = dynstr_cat_many(src, src, src, src, src, NULL);
Dynstr *dog = dynstr_substr(cat, 15, 5);

Let the library take care of memory allocations and related tracking, and concentrate on real problem solving instead. We did this in Kannel, back in 1999, and it wiped out all the buffer overflow problems (until a co-worker decided it was "more efficient" to use native C strings instead, promptly introducing a buffer overflow). All of this string handling is, of course, way nicer in higher level languages. In fact, whenever you need to deal with string handling in C, it is probably a sign that you should consider switching to a higher level language instead. But whatever you do, stop claiming that strncpy is safe or solves any real problems strcpy has. Update: Fixed "It does terminate" to say "It does not terminate". Thanks to Matthew Garrett for pointing that out. Update2: Fixed example call to snprintf. Update3: Fixed the test for snprintf example. Thanks, Redditor axylone. Also pointed out that snprintf is slower than the rest.