Adapt VERSION_REGEXP for EnvironmentModules

When using an Environment Modules version built from git repository,
version number contains git branch name, number of commit since last
released version and commit hash.

This commit adapts VERSION_REGEXP for EnvironmentModules class to allow
using development or locally adapted versions of Environment Modules
with EasyBuild.

Fixes #4126

easybuild/tools/modules.py

@@ -1326,7 +1326,7 @@ class EnvironmentModules(EnvironmentModulesTcl):
     COMMAND_ENVIRONMENT = 'MODULES_CMD'
     REQ_VERSION = '4.0.0'
     MAX_VERSION = None
-    VERSION_REGEXP = r'^Modules\s+Release\s+(?P<version>\d\S*)\s'
+    VERSION_REGEXP = r'^Modules\s+Release\s+(?P<version>\d[^+\s]*)(\+\S*)?\s'
 
     def __init__(self, *args, **kwargs):
         """Constructor, set Environment Modules-specific class variable values."""

test/framework/modulestool.py

@@ -209,6 +209,21 @@ def test_environment_modules_specific(self):
             mt = EnvironmentModules(testing=True)
             self.assertIsInstance(mt.loaded_modules(), list)  # dummy usage
 
+            # initialize Environment Modules tool with non-official version number
+            # pass (fake) full path to 'modulecmd.tcl' via $MODULES_CMD
+            fake_path = os.path.join(self.test_installpath, 'libexec', 'modulecmd.tcl')
+            fake_modulecmd_txt = '\n'.join([
+                'puts stderr {Modules Release 5.3.1+unload-188-g14b6b59b (2023-10-21)}',
+                "puts {os.environ['FOO'] = 'foo'}",
+            ])
+            write_file(fake_path, fake_modulecmd_txt)
+            os.chmod(fake_path, stat.S_IRUSR | stat.S_IXUSR)
+            os.environ['_module_raw'] = "() {  eval `%s' bash $*`;\n}" % fake_path
+            os.environ['MODULES_CMD'] = fake_path
+            EnvironmentModules.COMMAND = fake_path
+            mt = EnvironmentModules(testing=True)
+            self.assertTrue(os.path.samefile(mt.cmd, fake_path), "%s - %s" % (mt.cmd, fake_path))
+
     def tearDown(self):
         """Testcase cleanup."""
         super(ModulesToolTest, self).tearDown()