%pyproject_save_files: Add a workaround error for spaces and [brackets]

See the added links for details.
We cannot fix this for now,
so we error out early instead of producing a broken filelist.
Related: rhbz#1950291

pyproject-rpm-macros.spec

@@ -121,6 +121,7 @@ export HOSTNAME="rpmbuild"  # to speedup tox in network-less mock, see rhbz#1856
 %changelog
 * Thu Sep 09 2021 Miro Hrončok <mhroncok@redhat.com> - 0-47
 - %%pyproject_save_files: Expand the namespace error message, also display it with /
+- %%pyproject_save_files: Add a workaround error for spaces and [brackets]
 
 * Fri Jul 23 2021 Miro Hrončok <miro@hroncok.cz> - 0-46
 - %%pyproject_buildrequires now fails when it encounters an invalid requirement

pyproject_save_files.py

@@ -240,7 +240,8 @@ def escape_rpm_path(path):
     unless we put it in "quotes".
     Or a literal % symbol in path might be expanded as a macro if not escaped.
 
-    Due to limitations in RPM, paths with spaces and double quotes are not supported.
+    Due to limitations in RPM,
+    some paths with spaces and other special characters are not supported.
 
     Examples:
 
@@ -263,6 +264,11 @@ def escape_rpm_path(path):
         Traceback (most recent call last):
           ...
         NotImplementedError: ...
+
+        >>> escape_rpm_path('/usr/share/data/spaces and [square brackets]')
+        Traceback (most recent call last):
+          ...
+        NotImplementedError: ...
     """
     orig_path = path = str(path)
     if "%" in path:
@@ -275,6 +281,10 @@ def escape_rpm_path(path):
             # As far as we know, RPM cannot list such file individually
             # See this thread http://lists.rpm.org/pipermail/rpm-list/2021-June/002048.html
             raise NotImplementedError(f'" symbol in path with spaces is not supported by %pyproject_save_files: {orig_path!r}')
+        if "[" in path or "]" in path:
+            # See https://bugzilla.redhat.com/show_bug.cgi?id=1990879
+            # and https://github.com/rpm-software-management/rpm/issues/1749
+            raise NotImplementedError(f'[ or ] symbol in path with spaces is not supported by %pyproject_save_files: {orig_path!r}')
         return f'"{path}"'
     return path