I'm running into issues with build-and-provide not updating the cowbuilder environment. This seems to be caused by a lock file that must have been left behind on an earlier run:

<jenkins5:~ >ls /var/run/lock/jessie-amd64.update -l
-rw-r--r-- 1 jenkins-slave jenkins-slave 0 Jun  1 10:20 /var/run/lock/jessie-amd64.update                                                                                          

I'm not sure why these lock files are left behind but this has happened multiple times on one of our build slaves. But I guess the why doesn't matter too much (it could just be the result of a crashed executor). Anyway, the issue is detected by build-and-provide correctly

15:45:30 + echo '*** Update run already taking place, skipping ***'
15:45:30 *** Update run already taking place, skipping ***

Unfortunately it seems to handle this case in the wrong way. It just prints the warning, skips the cowbuilder update and proceeds. As a consequence I end up with a cowbuilder environment that has not seen an apt-get update run for weeks causing builds against old versions of my libraries.

@mika: I'm still a bit confused by some details of the locking code (the 9> part in particular) but overall it makes sense to me - except for the following line: 9c37df2#diff-8d65555d96716579f851f18d113e9d79R331 Can you please elaborate a bit on your intentions? I believe we should at least sleep until the lock file goes away. We definitely shouldn't proceed with the build if we aren't 100% sure that our cowbuilder environment has actually successfully (and completely!) been updated. Even if another cowbuilder --update run is underway we should wait until it's done and then start our own update run. This would make sure we never miss the latest version of our build dependencies.