Possible return codes

[rmccrack]

Two-part question:

1. What are the possible return codes "rear -v mkrescue" might issue to a calling program/script?
2. Is there any circumstance when "rear -v mkrescue" might issue a return code indicating failure, yet finish creating the iso image?

[jsmeix]

As far as I see the only normal exit codes are 0, 1, and 143
see usr/sbin/rear (excerpts)

# When this point is reached, the workflow is done without a real error because
# for real errors one of the Error functions should be called that kills rear and
# then the exit code is usually 143 = 128 + 15 (15 = SIGTERM from the USR1 trap)
...
            # The checklayout workflow is special because it sets EXIT_CODE=1
            # when the disk layout has changed or when configuration files have changed
            # but that exit code 1 is no error but meant as a signal that things have changed
            # which require a new ISO image so that users can run "rear checklayout || rear mkrescue"
            # see https://github.com/rear/rear/issues/564

The only other place except the checklayout workflow where EXIT_CODE=1 is set is in
usr/share/rear/layout/save/NSR/default/650_check_iso_recoverable.sh

So except the checklayout workflow and except NSR
the exit code 143 happens when ReaR errors out
otherwise the exit code is 0 when ReaR finishes.

When ReaR finishes with exit code 0 it does not mean all is actually well.
Exit code 0 only means ReaR did not error out (so things look OK).
Cf. "Try hard to care about possible errors" in
https://github.com/rear/rear/wiki/Coding-Style
See also "No disaster recovery without testing and continuous validation" in
https://en.opensuse.org/SDB:Disaster_Recovery