Thanks Christian for your initial investigations! I'm back from
vacation, looking into this now. Observations:

 * The 0.13 tests still work fine
<https://autopkgtest.ubuntu.com/packages/f/fatrace/groovy/amd64>, so
this is indeed a problem with the "new" FAN_REPORT_FID mode.

 * I finally moved the upstream code from git.lauchpad.net to github
<https://github.com/martinpitt/fatrace> and added Travis integration for
Ubuntu 20.04 LTS: This worked: https://travis-
ci.com/github/martinpitt/fatrace/builds/180931055 (also a previous run
on the tests branch).

 * I can in principle reproduce this on my Fedora 32 host (kernel
5.7.10), but it's really difficult -- I only got one failure in about
100 runs. This was when I had quite some background noise (downloading a
VM image), and thus a lot of events that were unrelated to the test.

 * After the image download finished, and thus background noise ceased,
I can no longer reproduce this.

 * I tried in an Ubuntu 20.04 VM, and after some dozen iterations I get
a *different* type of failure:

   ^bash(.* C\?WO\? /root/fatrace/test.txt not found in log

     bash(8605): CO /etc/ld.so.cache
     [...]
     unknown(8605): CWO /root/fatrace/test.txt


   ^rm(.*): D /root/fatrace$ not found in log

     rm(10115): O /usr/lib/locale/C.UTF-8/LC_NUMERIC
     rm(10115): O /usr/lib/locale/C.UTF-8/LC_CTYPE
     unknown(10115): D /root/fatrace
     unknown(10115): C /usr/bin/rm

   My first Travis run <https://travis-
ci.com/github/martinpitt/fatrace/builds/180930904> had something
similar.

  This is again the ancient race condition of /proc/pid/comm being out
of sync with the actual process -- there is no race free way how to map
the fanotify event to a process exec. To fix this, I could cache the
lookup result for a while, but of course it would then be subject to pid
re-use.

  But either way, this is a different failure than this bug report.

 * I can make the locally running test fail when creating background
noise with

       find . -exec head '{}' \; > /dev/null

   But it usually just fails with the "unknown" error.

So it seems I should first do something about that "/proc/pid/comm out
of sync" issue.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1885188

Title:
  fatrace autopkgtest failure due to rename test

To manage notifications about this bug go to:
https://bugs.launchpad.net/fatrace/+bug/1885188/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to