nailing-cargo: oot_massage_cmdline: Initialise $pre and $post

Otherwise if we don't write anything to them, we produce an undef
warning.

No functional change with current code.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/nailing-cargo b/nailing-cargo
index cef0808803d46e9260b6e55afb69c2dd2eab0dfa..8eb65ec6308334af724a8777b2b79c80651ef433 100755 (executable)
--- a/nailing-cargo
+++ b/nailing-cargo
@@ -500,7 +500,7 @@ sub oot_massage_cmdline () {
   $use // die "$self: out-of-tree build, but \`oot.use' not configured\n";
   $build_absdir = "$oot_absdir/$subdir";
 
-  my ($pre,$post);
+  my ($pre,$post) = ('','');
   my @xargs;
   if (!$cargo_lock_update) {
     push @xargs, $build_absdir;