strange make test, make test finishing in the middle of a run

[Matthieu Patou]

Hello while making a make test today with the waf build I get this:

[402/626 in 11m26s] samba4.raw.sfileinfo (dc)
[403/626 in 11m27s] samba4.raw.search (dc)
Traceback (most recent call last):
   File "../selftest/filter-subunit", line 49, in <module>
     sys.exit(subunithelper.parse_results(msg_ops, statistics, sys.stdin))
   File "/usr/local/src/samba4/selftest/subunithelper.py", line 117, in 
parse_results
     open_tests.remove(testname)
ValueError: list.remove(x): x not in list
Testing OS/2 style delete on 700 files
UNEXPECTED(error): samba4.raw.search (dc).os2 delete
REASON: was started but never finished!


A summary with detailed information can be found in:
   ./st/summary

ALL OK (1905 tests in 402 testsuites)

And after the test was going on ...
I had this more than once even after a make clean.
What can it be ?

Matthieu