Hi, I just wrote an export script that returns an appropriate exit code. 0 means everything's fine, everything else means something went wrong. However BSS always says that everything is fine. You can check it yourself with this script:
#!/bin/sh
echo "starting script..."
(>&2 echo "error, something went wrong")
exit 1
The expected behaviour is that BSS shows that an error occured in the toast, containing a link to "more information" or "show details". Behind that link one should see all STDERR (and maybe STDOUT, too).