nailing-cargo: Fix handling of missing oot.use

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

diff --git a/nailing-cargo b/nailing-cargo
index e737d78734607405e3671ae4d4c01f3a1bbda909..72abb09f9573c844615615a86da85c4502cbe061 100755 (executable)
--- a/nailing-cargo
+++ b/nailing-cargo
@@ -283,7 +283,7 @@ sub consider_oot () {
     $cargo_lock_update=0;
     return;
   }
-  if ($use eq 'disable') {
+  if (($use//'') eq 'disable') {
     $oot_dir = undef;
     return;
   }
@@ -406,6 +406,7 @@ sub oot_massage_cmdline () {
   return unless defined $oot_dir;
 
   my $use = cfgs qw(oot use);
+  $use // die "$self: out-of-tree build, but \`oot.use' not configured\n";
   $oot_absdir = ($oot_dir !~ m{^/} ? "$worksphere/" : ""). $oot_dir;
   $build_absdir = "$oot_absdir/$subdir";