run sanity checks commands from an empty temporary directory (rather than the software install directory)

easybuild/framework/easyblock.py

@@ -3739,16 +3739,16 @@ def xs2str(xs):
         if self.toolchain.mpi_family() and self.toolchain.mpi_family() in toolchain.OPENMPI:
             env.setvar('OMPI_MCA_rmaps_base_oversubscribe', '1')
 
-        # change to install directory (better environment for running tests)
-        if os.path.isdir(self.installdir):
-            change_dir(self.installdir)
+        # run sanity checks from an empty temp directory
+        # using the build or installation directory can produce false positives and polute them with files
+        sanity_check_work_dir = tempfile.mkdtemp(prefix='eb-sanity-check-')
 
         # run sanity check commands
         for cmd in commands:
 
             trace_msg(f"running command '{cmd}' ...")
 
-            res = run_shell_cmd(cmd, fail_on_error=False, hidden=True)
+            res = run_shell_cmd(cmd, work_dir=sanity_check_work_dir, fail_on_error=False, hidden=True)
             if res.exit_code != EasyBuildExit.SUCCESS:
                 fail_msg = f"sanity check command {cmd} failed with exit code {res.exit_code} (output: {res.output})"
                 self.sanity_check_fail_msgs.append(fail_msg)
@@ -3802,8 +3802,8 @@ def xs2str(xs):
                 "Sanity check failed: " + '\n'.join(self.sanity_check_fail_msgs),
                 exit_code=EasyBuildExit.FAIL_SANITY_CHECK,
             )
-        else:
-            self.log.debug("Sanity check passed!")
+
+        self.log.debug("Sanity check passed!")
 
     def _set_module_as_default(self, fake=False):
         """

test/framework/toy_build.py

@@ -2373,6 +2373,8 @@ def test_toy_sanity_check_commands(self):
         test_easyconfigs = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'easyconfigs', 'test_ecs')
         toy_ec_txt = read_file(os.path.join(test_easyconfigs, 't', 'toy', 'toy-0.0.eb'))
 
+        out_file = os.path.join(self.test_prefix, 'out.txt')
+
         toy_ec_txt = '\n'.join([
             toy_ec_txt,
             "toolchain = {'name': 'foss', 'version': '2018a'}",
@@ -2388,6 +2390,8 @@ def test_toy_sanity_check_commands(self):
             "   True,",
             # test command to make sure that '-h' is not passed to commands specified as string ('env -h' fails)
             "   'env',"
+            # print current working directory, should *not* be software install directory, but empty dir
+            f"   '(pwd && ls | wc -l) > {out_file}',",
             "]",
         ])
 
@@ -2412,6 +2416,13 @@ def test_toy_sanity_check_commands(self):
 
         self.assertExists(toy_modfile)
 
+        # check contents of output file created by sanity check commands
+        self.assertExists(out_file)
+        out_txt = read_file(out_file)
+        # working dir for sanity check command should be an empty custom temporary directory
+        regex = re.compile('^.*/eb-[^/]+/eb-sanity-check-[^/]+\n[ ]*0$')
+        self.assertTrue(regex.match(out_txt), f"Pattern '{regex.pattern}' should match in: {out_txt}")
+
     def test_sanity_check_paths_lib64(self):
         """Test whether fallback in sanity check for lib64/ equivalents of library files works."""
         test_ecs_dir = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'easyconfigs')