fix uninit warnings

diff --git a/lib/local/lib.pm b/lib/local/lib.pm
index f5e4778..80f56ad 100644 (file)
--- a/lib/local/lib.pm
+++ b/lib/local/lib.pm
@@ -314,7 +314,8 @@ sub environment_vars_string_for {
       next;
     }
     if (!ref $value
-        && $value eq $ENV{$name}) {
+        && defined $value ? $value eq $ENV{$name} : !defined $ENV{$name}
+    ) {
       next;
     }
     $out .= $self->$build_method($name, $value);