Fix erroneous exit code not propagating for BatchJob

[taueres]

BatchJob was not correctly propagating erroneous exit codes of its child processes.

If you are looking for bug replication this commit is useful taueres@748dabd (Dockerfile included).

[stof]

this needs a test covering it

[taueres]

@stof I just added tests.

[stof]

shouldn't we rather have a case throwing an exception in the closure ? This seems a more sensible use case.

[taueres]

Exceptions are indeed more sensible use cases. But this way we cannot test the correctness of the exit status.

[taueres]

@stof I just added a new test case when the closure throws an exception.

[taueres]

@stof Fixed test messages

[kgilden]

The state is indeed propagated but what happens if a child fork throws an exception? Would be very nice to know what exactly went wrong. Or do child forks in that case print the message to stderr?

[taueres]

@stof @kgilden Now exception messages are correctly propagating up to the main process.
With this fix only error messages are kept, since the original exception is not available.

Do you have any better solution?

[stof]

do we absolutely need to exit here ? It would be great if this example could match what people will probably do, i.e. not using exit at all

[stof]

@taueres I don't have experience with Spork, so this would need to be reviewed by @kriswallsmith (it is needed anyway as he is the only maintainer)

[binarious]

Any news?

[Algatux]

@kriswallsmith any new about this pr? thx

[kriswallsmith]

My concern here and the reason I have left it as it is for now is that the user will have no way to know which items in the batch job have processed and which were not. Do you think this a valid concern, or should we say batch jobs must be idempotent so the batch job can simply be run again if something goes wrong?

[kgilden]

@kriswallsmith It does seem like a valid concern. However, I think it's a fair compromise to require idempotence from the jobs. Because at present moment users still can't get any straight-forward information regarding which of the jobs failed. Just my 5¢.