act_runner mangles boolean input defaults: format('{0}', inputs.warnaserror)
evaluated to '%!t(string=false)', so -warnaserror was never passed.
Input is now a string defaulting to "true"; anything but "false" enables it.
Build command is traced (set -x) so the log shows the flags used.
Co-Authored-By: Claude Opus 5.5 <[email protected]>