Fix

Author: danog

.github/nightly.php

@@ -243,7 +243,7 @@ function (): iterable {
             }
             printMutex(
                 "$dir ($rev): $cmd terminated with status $status:".PHP_EOL
-                .file_get_contents($result).PHP_EOL
+                .file_get_contents($output).PHP_EOL
             );
         }