Starting recently, the test_intpack series of unit tests are failing on OSX.

I have managed to reproduce this on OSX, the failure appears to have been going on for quite some time.

Failure itself looks to be some form of timing error around deleting of files within the test environment. The test is also only triggered when run with concurrency (-j >1) and passes when run in serial.

Command to repro:

DYLD_LIBRARY_PATH=.libs python ../test/suite/run.py -v 2 test_intpack -j 4