Infinite loop in the slave with Mercurial

[kalessin]

Hello,

I have set up a buildbot for my first time (you do cool things !) and I have fallen into a nasty bug.

I'm using buidlbot (slave and master) on Debian squeeze with mercurial:

(chroot)root@kalessin:/tmp# buildbot --version
Buildbot version: 0.7.11p3
Twisted version: 9.0.0
(chroot)root@kalessin:/tmp# hg --version
Mercurial Distributed SCM (version 1.4.1)

Copyright (C) 2005-2009 Matt Mackall <mpm@selenic.com> and others
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
(chroot)root@kalessin:/tmp# 

Whenever a new build was launched the slave started an infinite loop. The reason was here :

 http://github.com/djmitche/buildbot/blob/master/buildbot/slave/commands.py#L2915

You compare two directories paths, but done this way /foo/bar and /foo/bar/ appears to be differents. In my case when the condition was true, the slave restarted a complete checkout of the code, falling again in the condition, and again, and again, and again...

I have resolved the problem, by setting my repourl in my master.cfg without the ending slash :

from buildbot.process import factory
from buildbot.steps.source import Mercurial
from buildbot.steps.shell import Compile, Configure, Test
f1 = factory.BuildFactory()
f1.addStep(Mercurial(repourl="/tmp/zia"))
f1.addStep(Configure(command=["cmake", "."])) # do not use configure
f1.addStep(Compile()) # make all
f1.addStep(Test()) # make test

A more robust way to compare directories paths should be used.

Please, find the log from both the slave and the master attached with this ticket. (due to the loop I have truncated them).

Best Regards -- Louis Opter <kalessin@…>

[kalessin]

Log file from the slave

[kalessin]

Log file from the master

[kalessin]

Correct version number.

[kalessin]

Correct the title...

[marcusl]

Good catch.

Could you check if this is still present in 0.7.12? IIRC some work was done the comparison code, but I'm not sure whether this bug was affected.

[marcusl]

Try to add this before the comparison, to remove trailing slashes from either path:

   oldurl = oldurl.rstrip('/')
   newurl = oldurl.rstrip('/')

[marcusl]

bah.. obvious typo there.. and no edit of comments.. sigh..

[Dustin J. Mitchell]

compare mercurial repos without trailing slashes (fixes #694)

This simply strips the trailing slashes from the repositories before comparing the strings. This may be covering up a deeper problem, though.

Changeset: f45d016cf0f47dfbb16d1117c1f5ebe1141f8026

[dustin]

Well, let me know if this fixed it - it's just a more subtle version of marcus's patch.

[marcusl]

It's probably nothing more than the fact that the slash is appended/removed by Mercurial and users can specify with or without, and it still works.

[tyleroderkirk]

I encountered an infinite loop similar to the submitter's on Ubuntu 9.04 with Buildbot 0.7.12 while trying to build code from a local Mercurial repository.

Dustin's patch above (changeset:f45d016cf0f47dfbb16d1117c1f5ebe1141f8026) didn't resolve it but changing the repository URL in my master.cfg from "file:///var/lib/foo" to "/var/lib/foo" did.

So, I'm all set, but shout if you need any more details.

[marcusl]

Right. We should strip  file:// from both URLs that we compare with, not just the one that hg gives us.

And there should be some protection against infinite loops anyway.

[Marcus Lindblom]

Avoid infinite recursion in Mercurial step (see #694)

Changeset: ad4a73471d2f3c5147ef1c4bc5717c7919502123

[marcusl]

Fix Mercurial repo URL comparison for clobber (fixes #694)

Changeset: 60b285b6efa45e8dbdaea542a64b354207aecae9

[Marcus Lindblom]

Avoid infinite recursion in Mercurial step (see #694)

Changeset: ad4a73471d2f3c5147ef1c4bc5717c7919502123