spawn: reinstate directory existence check

We must not attempt to use Inline::C unless a user requests
it (by creating the directory) or running lei.

Fixes: ebdccd6666f9 (spawn: drop checks for directory writability)

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index ec256698..265638fe 100644
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -287,6 +287,7 @@ ALL_LIBC
                         $ENV{XDG_CACHE_HOME} //
                         ( ($ENV{HOME} // '/nonexistent').'/.cache' )
                 ).'/public-inbox/inline-c';
+        undef $all_libc unless -d $inline_dir;
         if (defined $all_libc) {
                 local $ENV{PERL_INLINE_DIRECTORY} = $inline_dir;
                 use autodie;