Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS CrayCCE-20.08.eb

Build succeeded for 1 out of 1 (1 easyconfigs in total)
daint102 - Linux UNKNOWN UNKNOWN, x86_64, Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz, Python 2.7.17
See https://gist.github.com/6b94b420fd1fd84b0c123b8983dcd845 for a full test report.

@gppezzi @victorusu @lucamar @vkarak Any thoughts on this?

@boegel lgtm. It makes sense, since I've seen this behaviour as well.

Thanks for the comment @boegel: I think that we used on some system the CSCS custom script craytoolchain.py to cope with a bug in Modules 4.0 and 4.1, where unloading an non existing modulefile generates an "Unable to locate modulefile" error.
Starting with version 4.2, unloading a module only looks at loaded module list and does not trigger a modulefile search: so starting version 4.2 the same behavior than Modules compatibility version 3.2 is obtained (section unload in https://modules.readthedocs.io/en/latest/diff_v3_v4.html).

The difference was the use of the array AVAIL_PRGENVS instead of KNOWN_PRGENVS to iterate prgenv:

AVAIL_PRGENVS=[]
for prgenv in [prgenv for prgenv in KNOWN_PRGENVS]:
    try:
        subprocess.check_call("module unload %s &> /dev/null" % prgenv, shell=True)
        AVAIL_PRGENVS.append(prgenv)
    except subprocess.CalledProcessError:
        continue