Repository: ros-infrastructure/catkin_pkg

Issue:
Attribute Error with docutils 0.19
Debian testing received an update of docutils from 0.17.1 to 0.19. Now this AttributeError is thrown

```  
  File "/usr/lib/python3/dist-packages/catkin_pkg/cli/tag_changelog.py", line 31, in get_forthcoming_label
    title_text = title.children[0].rawsource
AttributeError: 'Text' object has no attribute 'rawsource'. Did you mean: 'source'?
```

`rawsource` was removed in 0.18 according to the [release notes](http://www.docutils.org/RELEASE-NOTES.html#release-0-18-2021-10-26)
> Removed attributes:
>   * nodes.Text.rawsource: we store the null-escaped text in Text nodes since 0.16 so there is no additional information in the rawsource.

Discussion:

Solution patch:
diff --git a/src/catkin_pkg/cli/tag_changelog.py b/src/catkin_pkg/cli/tag_changelog.py
index b0573432..e2fbe954 100644
--- a/src/catkin_pkg/cli/tag_changelog.py
+++ b/src/catkin_pkg/cli/tag_changelog.py
@@ -28,7 +28,7 @@ def get_forthcoming_label(rst):
             if len(section.children) > 0 and isinstance(section.children[0], docutils.nodes.title):
                 title = section.children[0]
         if title and len(title.children) > 0 and isinstance(title.children[0], docutils.nodes.Text):
-            title_text = title.children[0].rawsource
+            title_text = title.children[0]
             if FORTHCOMING_LABEL.lower() in title_text.lower():
                 if forthcoming_label:
                     raise RuntimeError('Found multiple forthcoming sections')


Test patch:
diff --git a/test/test_tag_changelog.py b/test/test_tag_changelog.py
new file mode 100644
index 00000000..a5b49c90
--- /dev/null
+++ b/test/test_tag_changelog.py
@@ -0,0 +1,43 @@
+# coding=utf-8
+
+from catkin_pkg.cli.tag_changelog import get_forthcoming_label
+from catkin_pkg.cli.tag_changelog import rename_section
+
+single_forthcoming_rst = """\
+^^^^^^^^^^^^^^^^^^^^^^^^^
+Changelog for package foo
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Forthcoming
+-----------
+
+* Initial release
+* Initial bugs
+* Contributors: Sömeöne with UTF-8 in their name
+"""
+
+single_version_rst = """\
+^^^^^^^^^^^^^^^^^^^^^^^^^
+Changelog for package foo
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+0.0.1 (2012-01-31)
+------------------
+
+* Initial release
+* Initial bugs
+* Contributors: Sömeöne with UTF-8 in their name
+"""
+
+
+def test_get_forthcoming_label():
+    assert get_forthcoming_label(single_version_rst) is None
+    assert get_forthcoming_label(single_forthcoming_rst) == 'Forthcoming'
+
+
+def test_rename_section():
+    res = rename_section(
+        single_forthcoming_rst,
+        'Forthcoming',
+        '0.0.1 (2012-01-31)')
+    assert res == single_version_rst