scripts/setlocalversion: add more comments to -dirty flag detection
This script stumbled on the read-only source tree over again:
-
a2bb90a08cb3 ("kbuild: fix delay in setlocalversion on readonly
source")
-
cdf2bc632ebc ("scripts/setlocalversion on write-protected source
tree")
-
8ef14c2c41d9 ("Revert "scripts/setlocalversion: git: Make -dirty
check more robust"")
-
ff64dd485730 ("scripts/setlocalversion: Improve -dirty check with
git-status --no-optional-locks")
Add comments to clarify that this script should never ever try to write
to the source tree.
'git describe --dirty' might look as a simple solution for appending
the -dirty string, but we cannot use it because it creates the
.git/index.lock file.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>