Rewrite coverage paths

Since tox is running tests on the installed package, the coverage paths are no
more relative to the repository root.

.gitlab-scripts/rewrite-coverage-paths.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+import sys
+import xml.etree.ElementTree as ET
+
+
+def _replace_path(root, tag, attribute, old_prefix, new_prefix):
+    for element in root.iter(tag):
+        original_path = element.get(attribute)
+
+        if old_prefix and original_path.startswith(old_prefix):
+            new_path = original_path.replace(old_prefix, new_prefix, 1)
+            element.set(attribute, new_path)
+        elif not old_prefix:
+            new_path = new_prefix + original_path
+            element.set(attribute, new_path)
+
+
+def rewrite_coverage_xml(file_path, old_prefix, new_prefix):
+    tree = ET.parse(file_path)
+    root = tree.getroot()
+
+    if root.tag == 'coverage':
+        _replace_path(root, 'class', 'filename', old_prefix, new_prefix)
+    elif root.tag == 'testsuites':
+        _replace_path(root, 'testcase', 'file', old_prefix, new_prefix)
+
+    tree.write(file_path)
+
+
+if __name__ == "__main__":
+    old_prefix, new_prefix, *file_paths = sys.argv[1:]
+    for file_path in file_paths:
+        rewrite_coverage_xml(file_path, old_prefix, new_prefix)