scripts: sphinx-pre-install: report broken venv

After distro upgrades, the directory names for python may change.
On such case, the previously-created venv will be broken, and
sphinx-build won't run.

Add a logic to report it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/f117f03555b0636d2be0b68f3a23b1d3f03ccf1d.1656756450.git.mchehab@kernel.org
[jc: fixed typo in warning message]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/scripts/sphinx-pre-install b/scripts/sphinx-pre-install
index ae8c497..cfb82c5 100755 (executable)
--- a/scripts/sphinx-pre-install
+++ b/scripts/sphinx-pre-install
@@ -720,6 +720,12 @@ sub get_virtenv()
                next if (! -f $sphinx_cmd);
 
                my $ver = get_sphinx_version($sphinx_cmd);
+
+               if (!$ver) {
+                       $f =~ s#/bin/activate##;
+                       print("Warning: virtual environment $f is not working.\nPython version upgrade? Remove it with:\n\n\trm -rf $f\n\n");
+               }
+
                if ($need_sphinx && ($ver ge $min_version)) {
                        return ($f, $ver);
                } elsif ($ver gt $cur_version) {