Josef “Jeff” Sipek

It took me about 3 years to write this post. Partly because I had other things I wanted to work on and partly because I hoped that it wouldn’t be needed. Well, I finally decided that I really need to write this.

In short, I’m officially stopping work on guilt.

Practically speaking, I haven’t touched it (as a developer) in over two years and as a user in about as long. So really, nothing will change.

What is guilt?

I started writing Guilt in fall 2006 because I was working on unionfs and needed to maintain patches on top of the Linux kernel git repository—much like what the mq extension did with Mercurial repositories.

It all started with:

commit 664e5a7d7f8d2c2726f03a239de11fa00127cf84
Author: Josef Sipek <jsipek@thor.fsl.cs.sunysb.edu>
Date:   Mon Nov 6 13:08:30 2006 -0500

    Initial commit

That’s right, 14 years to the day.

Technically, the first few versions were called “gq” (which stood for “git quilt”) until someone pointed out that “GQ” was a well established GTK-based LDAP client.

Artifacts

If anyone wishes to resurrect this project, then by all means go for it. If not, the old content will remain online for as long as I have a web server. :)

Specifically, you can find everything up to and including the last release (v0.37-rc1) at the following locations:

• HTML manpages: http://guilt.31bits.net/man/
• Source tarballs: http://guilt.31bits.net/src/
• Git repository: https://repo.or.cz/guilt.git (mirrored at https://github.com/jeffpc/guilt)

Users

I know that Guilt has served a number of people quite well over the years. It’s been quite stable and mostly feature complete since at least 2008, so I haven’t really been hearing from people short of the occasional patch or an occasional “oh yeah, I use that”.

To those users: I hope the last release works well enough for you until someone starts to maintain Guilt again or you find a different tool that suits your needs.

Over the past few months, I’ve played with Solaris — specifically, OpenIndiana, or OI for short. OI is a fork of OpenSolaris. OI’s first release happened on September 14, 2010. Today, exactly a year later, the OI community is proud to annouce the release of build 151a. The release notes say it all.

Personally, I find the KVM port to Illumos (the project that forked the core libs, programs, and OpenSolaris kernel) the most interesting. It’ll let me run (and manage!) virtual machines a bit more easily than what I get with VirtualBox. (Since OI now uses Illumos as the core Solaris upstream, it benefits from all the great work done by companies and individuals that contribute to Illumos.)

In case you are a bit confused, OI aims to be the defacto community Solaris distribution.

Oh, I almost forgot… 151a includes a package with Guilt (developer/versioning/guilt). :)

Yeah, I really wanted to write this yesterday — since it is about yesterday, but I was too tired when I got to the hotel. Either way, here it is.

The day started at 10am again - I love it. Previous years, presentations started at 9am (except the first day that was 10am). The first talk I attended was a about kernel documentation — where it resides, and why the current state is bad. The talk was a bit confusing. At one point, the presenter decided to read some text right from a HTML file — opening it in a text editor instead of a browser. He also seemed to contradict himself a bit … at one point he seemed to have said that HTML was better than plaintext docs, and then some time later, he said the other thing — plaintext docs were better than HTML. I kinda gave up understanding what his point was.

I decided to be lazy, and stayed in the same room for the next talk: On submitting kernel features. I zoned out for quite a bit — I knew a bunch of things already, and it was a bit hard to lex what Andi Kleen (the speaker) was saying.

I was going to go to the ext4 talk. Unfortunately, I got distracted by people on my way to the talk, and before I knew it, I missed most of it. I guess I’ll just have to read the paper.

After lunch, I went to Virtualization of Linux servers: a comparative study. The talk was interesting, and I will read the paper. It showed exactly how much x86 virtualization sucks (at least compared to what’s on the mainframe). I can’t wait to have some time to hack on HVF some more. :)

Then, I got distracted by people, preparation of slides for my BOF about Guilt, pondering about trying SELinux again, etc., etc.

Anyway, I’m going to finish a summary of what happened yesterday later today. Until then…

Ok, so after doing all that work on Guilt, I decided that it would be an interesting experiment to resurect an idea I had about 2.5 years ago…my own kernel patch series. Back then, I called it -js, for rather obvious reasons (my name, if you haven’t noticed).

I wrote a small script, which allows me to make a release of a 2.6-js kernel patch series within seconds. I have no idea if it is worth anything having yet another kernel patch series, and I might not actually maintain it for long, but just in case someone is brave enough to try it, here it is: http://www.fsl.cs.sunysb.edu/~jsipek/kernel/js/. Yeah, I could put it on kernel.org, but I won’t unless I see that -js is actually getting somewhere.

Bug reports, etc. are..well..I guess, welcome :)

It is really interesting how sometimes a bit of luck makes things happen. For example, little over 6 months ago, I wrote a few shell scripts, which called gq, to make my life a little easier. I worked on the for about a week, and then I decided I should share with the community. So I tagged the sources as version 0.10, and announced it on the git mailing list. One of the comments I got was about the fact that there is another project (completely unrelated) that had the name gq for a long time. Oh well, it was time for me to rename it. After some procrastination and hacking, new year rolled around, and I decided to release 6th version (v0.15), but this time it wouldn’t be gq anymore — instead I would call it Guilt. My post from January describes how it got the name. As with every version of gq, I announced Guilt v0.15. I could see that Guilt was getting way better, and so I felt even more motivated to hack on it. v0.16 came out. And then a very unexpected thing happened. I got two patches from a guy on the mailing list. Sweet! I applied them, and release v0.17. Shortly thereafter, during the Linux Storage and Filesystem (LSF) workshop in San Jose, I got a patch from Ted Ts’o (of the ext[234] fame). I couldn’t believe it, but it was true. I decided to release v0.19 the next day. At LSF, I met Brandon Philips, and we talked about Guilt. Rather shortly after LSF, he send me an email saying that he’ll try to get Guilt into Debian. :) Well, about a month ago, he succeeded.

As many of you may already know, I stick around a number of channels on OFTC’s IRC network, and it is rather interesting to see people try Guilt, or people talk about Guilt; generally suggesting that someone use it — and people do!

Anyway, I hope I didn’t bore everyone to death with my little tour of history behind Guilt.

Quite a bit has changed in Guilt over the past two months. There have been 5 releases, as well as one release candidate (v0.19-rc1). During these releases, 71 files were changed (2210 insertions, 293 deletions) in 98 commits. There has been a number of patches I got via email:

Brandon Philips: 4
Nur Hussein: 3
Theodore Ts’o: 2
Yasushi SHOJI: 7

Brandon Philips contributed a significant portion of the documentation — currently every command has a man page! Additionally, he is trying to get Guilt picked up by Debian. So if you happen to qualify as a sponsor, do the right thing ;)

Nur Hussein contributed an uninstall script as well as fixed the patchbomb script.

As far as I know, Ted Ts’o is using Guilt to maintain his ext4 tree.

Yasushi contributed created a few patches which add several bits of quilt functionality (e.g., guilt-files, and guilt-series -v).

I have also been contacted by Peter Williams, the maintainer of gquilt (a GUI wrapper for quilt and mq, with a very similar name to guilt), if I would like to have guilt added as a backend. I checked out gquilt, and it looks really nice. I also looked at what it would take to add the backend, and it doesn’t look like that much effort, but I need to implement few bits of functionality first. If anyone wants to volunteer, let me or Peter know. :)

Here’s another update on my version control system escapades (a follow up to Do I have…).

As several people mentioned during the 0.10 release of gq, the name is already in use by a rather well established project. So, after some idleing and hacking, I decided that it was time to give the scripts a new name, and announce the new version on the git and linux-kernel mailing lists (the annoucement). I can’t take credit for the rather clever name, I asked a few people, and the best suggestion was by Dave - Git Quilt or Guilt for short.

One thing I did not expect was the fact that someone would contribute 2 patches very shortly after I announced it. Here’s the list of changes that made between v0.16 and v0.17:

Horst H. von Brand (2):
      Fix up Makefiles
      Run regression on the current version

Josef 'Jeff' Sipek (24):
      A minimalistic makefile
      Contributing doc file
      Added guilt-add
      Added guilt-status
      Expanded the HOWTO
      Added usage strings to all commands
      All arguments to guilt-add are filenames
      More thorough argument checking & display usage string on failure
      Changed status file format to include the hash of the commit
      Fixed guilt-refresh doing an unnecessary and somewhat wrong pop&push
      Fixed up guilt-{delete,pop} not matching the patch name properly
      Fixed guilt-{delete,pop} regexps some more
      Force UTC as timezone for regression tests
      Fixed a bug in guilt-pop introduced by the status file format switch
      Error messages should go to stderr
      Merge branch 'usage'
      Merge branch 'status-file'
      Yet another TODO update
      Added guilt-rm
      Makefile update & cleanup
      pop: Display the name of the patch from the status file, not the series file
      new: Create dir structure for the patch if necessary
      Documentation/TODO: Mark guilt-rm as done
      Guilt v0.17

I haven’t had much time to work on Guilt since then, but I got an rather encouriging email from someone, who tried to apply Andrew Morton’s -mm patch series on top of the kernel tree, but failed. The problem is with the way git-apply works. If it applies a patch with an offset, it still returns non-zero status. This makes guilt think that at least one of the hunks in the patch did not apply at all. As far as I know, there is no way to get the necessary information out of git-apply without either modifying it (which I might as well), or parsing the output for signs of rejection and ignoring the return status completely. I don’t like the latter, but changing git-apply would limit the number of compatible git versions. :-/

Needless to say, patches are welcomed :)

So, for whatever reason, I seem to be working on version control systems far too much. I have a decent amount of code in Mercurial, I wrote a bunch of wrappers for CVS, I call them CDS which stands for Completely Dumb System which is an apt description of CVS. And now I am working on gq (git repo: git://git.kernel.org/pub/scm/linux/kernel/git/jsipek/gq.git) which is a porcelain (set of wrapper scripts for git) that gives a Mercurial Queues-like functionality to git users.

Yep, I think it is official, I have a thing for version control systems. Ever since I became very interested in them (~April 2005), I learned a lot about them, and I am kind of tempted to give it a go and try something of my own. :)