Bug#816398: autopkgtest: build fails sporadically in OBS due to adt-run tests assuming lone builds

[Bob Ham]

Package: autopkgtest
Severity: serious
Justification: fails to build from source (but built successfully in the past)

Dear Maintainer,

There is a problem in the tests/adt-run python script which is run
while building the package in order to test adt-run.  The test
test_timeout_no_output asserts that there are no processes named
"adtsleep".  However, this assertion is only valid given the
assumption that the package will not be built alongside itself.  In
our instance of OBS, we can build i386 and amd64 on the same machine.
This means there can be and usually are, parallel builds of
autopkgtest, invalidating this assumption.  We get sporadic failures
of the build due to multiple instances of the adtsleep process.

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?

Trying to build autopkgtest in Open Build Service for both i386 and
amd64 at the same time.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?

Kicked off automated build, which builds for i386 and amd64.

   * What was the outcome of this action?

One of the builds failed:


======================================================================
FAIL: test_timeout_no_output (__main__.NullRunner)
handling test timeout for test without any output
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/adt-run", line 486, in test_timeout_no_output
      self.assertEqual(subprocess.getoutput('pidof adtsleep'), '')
      AssertionError: '2298' != ''
      - 2298
      +


----------------------------------------------------------------------
Ran 28 tests in 88.954s

FAILED (failures=1)
debian/rules:37: recipe for target 'override_dh_auto_test' failed
make[1]: *** [override_dh_auto_test] Error 1
make[1]: Leaving directory
'/usr/src/packages/BUILD/autopkgtest-3.6jessie1+co1'
debian/rules:28: recipe for target 'build' failed
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2


   * What outcome did you expect instead?

Successful build.


-- System Information:
Debian Release: 8.2
  APT prefers stable
  APT policy: (990, 'stable'), (500, 'stable-updates'), (70, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.4.0-linux-latest-99 (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: sysvinit (via /sbin/init)