ReFrame 3.3 and above broke support for Lmod < 8.2

When using the latest revision of reframe OR v3.3 every test results in:

------------------------------------------------------------------------------
FAILURE INFO for HelloWorldTestSerial_cpp_dynamic
  * Test Description: C++ Hello World Serial Dynamic
  * System partition: ubelix:gpu
  * Environment: foss
  * Stage directory: ~/ReFrame/stage/ubelix/gpu/foss/HelloWorldTestSerial_cpp_dynamic
  * Node list: None
  * Job type: batch job (id=None)
  * Dependencies (conceptual): []
  * Dependencies (actual): []
  * Maintainers: ['VH', 'EK']
  * Failing phase: compile
  * Rerun with '-n HelloWorldTestSerial_cpp_dynamic -p foss --system ubelix:gpu'
  * Reason: name error: name 'os' is not defined
Traceback (most recent call last):
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/frontend/executors/__init__.py", line 250, in _safe_call
    return fn(*args, **kwargs)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/pipeline.py", line 110, in _fn
    func(obj, *args, **kwargs)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/pipeline.py", line 124, in _wrapped
    return fn(*args, **kwargs)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/pipeline.py", line 1224, in compile
    trap_errors=True
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/schedulers/__init__.py", line 364, in prepare
    builder.write(runtime.emit_loadenv_commands(*environs))
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/runtime.py", line 235, in emit_loadenv_commands
    _, commands = loadenv(*environs)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/runtime.py", line 216, in loadenv
    load_seq = modules_system.load_module(**mod, force=True)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/modules.py", line 238, in load_module
    ret.append((m, self._load_module(m, force, collection)))
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/modules.py", line 252, in _load_module
    conflict_list = self._backend.conflicted_modules(module)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/modules.py", line 850, in conflicted_modules
    output = self.execute('show', str(module))
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/modules.py", line 411, in execute
    exec_output = self._execute(cmd, *args)
  File "/gpfs/homefs/id/id-svcrsitsm_conn/tmp/reframe/reframe/core/modules.py", line 743, in _execute
    exec(completed.stdout, {}, namespace)
  File "<string>", line 1, in <module>
NameError: name 'os' is not defined

I build ReFrame using:

git clone https://github.com/eth-cscs/reframe.git
cd reframe
./bootstrap.sh

and tried running: ./bin/reframe -v -c ../prgenv/ -n HelloWorldTestSerial_cpp_dynamic -r -C ../settings.py where the test cases has import os:

head ../prgenv/helloworld.py
from datetime import datetime
import os
import reframe as rfm
import reframe.utility.sanity as sn


class HelloWorldBaseTest(rfm.RegressionTest):
    def __init__(self, variant, lang, linkage):
        self.linkage = linkage

I get the same effect when I rebuild as follow and rerun:

git checkout v3.3
rm -rf external/*
./bootstrap.sh

BUT if I go back to v3.2 with the same procedure, the test runs fine.

In my configuration this is using the system python, which seems to work fine with the os package:

$ head -n 1 ./bin/reframe
#!/usr/bin/env python3
$ /usr/bin/env python3
Python 3.6.8 (default, Apr  2 2020, 13:34:55)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.isdir('~')
True

In my defined environments:foss and intel, both results to the system python as above. Is there something I am missing?

[mand35]

@vkarak, yes, we are using lmod.

[mand35]

Thanks a lot. Let me know if I can do something for you.