Apply suggestions from code review

Co-authored-by: Kenneth Hoste <[email protected]>

Author: Flamefire

easybuild/tools/filetools.py

@@ -1473,15 +1473,16 @@ def apply_regex_substitutions(paths, regex_subs, backup='.orig.eb', on_missing_m
     :param paths: list of paths to files to patch (or just a single filepath)
     :param regex_subs: list of substitutions to apply, specified as (<regexp pattern>, <replacement string>)
     :param backup: create backup of original file with specified suffix (no backup if value evaluates to False)
-    :param on_missing_match: Define what to do when the file when no match was found in the file.
+    :param on_missing_match: Define what to do when no match was found in the file.
                              Can be 'error' to raise an error, 'warn' to print a warning or 'ignore' to do nothing
                              Defaults to value of --strict
     """
     if on_missing_match is None:
         on_missing_match = build_option('strict')
-    ALLOWED_VALUES = (run.ERROR, run.WARN, run.IGNORE)
-    if on_missing_match not in ALLOWED_VALUES:
-        raise EasyBuildError('Invalid value passed to on_missing_match: %s', on_missing_match)
+    allowed_values = (run.ERROR, run.WARN, run.IGNORE)
+    if on_missing_match not in allowed_values:
+        raise EasyBuildError('Invalid value passed to on_missing_match: %s (allowed: %s)',
+                             on_missing_match, ', '.join(allowed_values))
 
     if isinstance(paths, string_type):
         paths = [paths]
@@ -1537,9 +1538,15 @@ def apply_regex_substitutions(paths, regex_subs, backup='.orig.eb', on_missing_m
                     if on_missing_match == run.ERROR:
                         raise EasyBuildError(msg)
                     elif on_missing_match == run.WARN:
-                        print_warning(msg)
+                        _log.warning(msg)
                     else:
-                        _log.info(msg)
+                        msg = 'Nothing found to replace in %s' % path
+                        if on_missing_match == run.ERROR:
+                            raise EasyBuildError(msg)
+                        elif on_missing_match == run.WARN:
+                            print_warning(msg)
+                        else:
+                            _log.info(msg)
 
             except (IOError, OSError) as err:
                 raise EasyBuildError("Failed to patch %s: %s", path, err)

test/framework/filetools.py

@@ -1208,7 +1208,7 @@ def test_apply_regex_substitutions(self):
             (r"^(FC\s*=\s*).*$", r"\1${FC}"),
             (r"^(.FLAGS)\s*=\s*-O3\s-g(.*)$", r"\1 = -O2\2"),
         ]
-        regex_subs_copy = regex_subs.copy()
+        regex_subs_copy = regex_subs[:]
         ft.apply_regex_substitutions(testfile, regex_subs)
 
         expected_testtxt = '\n'.join([