Intermittant test timeout failure

[clanmills]

The default for timeout is 20 seconds. Quite a long time for a little test. Yet, it frequently throws timeout on the MacMini and occasionally elsewhere.

======================================================================
2166FAIL: test_run (bugfixes.github.test_issue_1472.test_issue_1472Test)
2167----------------------------------------------------------------------
2168Traceback (most recent call last):
2169  File "/home/travis/build/Exiv2/exiv2/tests/system_tests.py", line 666, in test_run
2170    self.assertFalse(timeout["flag"], msg="Timeout reached")
2171AssertionError: True is not false : Timeout reached

The test is:

# -*- coding: utf-8 -*-

from system_tests import CaseMeta, CopyTmpFiles, path
@CopyTmpFiles("$data_path/test_issue_1472.jpg")

class test_issue_1472Test(metaclass=CaseMeta):

    filename  = path("$tmp_path/test_issue_1472.jpg")
    exvfile   = path("$tmp_path/test_issue_1472.exv")
    commands  = [ "rm     -rf                    $exvfile" 
                , "$exiv2 -pa --grep LensType2   $filename"
                , "$exiv2  ex                    $filename"
                , "$exiv2 -pa --grep LensType2   $exvfile"
                , "$exiv2  rm                    $filename"
                , "$exiv2 -pa --grep LensType2   $filename"
                , "$exiv2  in                    $filename"
                , "$exiv2 -pa --grep LensType2   $filename"
                ]
    stdout   =  [""
                ,"Exif.Sony2010e.LensType2                     Short       1  1024\n"
                ,""
                ,"Exif.Sony2010e.LensType2                     Short       1  1024\n"
                ,""
                ,""
                ,""
                ,"Exif.Sony2010e.LensType2                     Short       1  1024\n"
                ]
    stderr = [""]*len(commands)
    retval = [ 0,0,0,0,0,1,0,0]

The "slow" part is the insert command. This copies the metadata from the .exv into the JPEG.

The most irritating part of this is that the test suite terminates and doesn't proceed to run the version_test. I submitted a PR about that and Luis didn't like it because it had the side effect that $ make tests was always successful.