NodesTreeWidget: Red icon for failed processes

[danielhollas]

This has bugged me for a while. We were displaying green icon for processes that finished but had non-zero exit status.

BEFORE:

AFTER:

[yakutovicha]

I let @csadorf review it, as he mainly contributed to this part of the code.

[csadorf]

Generally no objections, but it seems a bit odd that we need to special case this. Do you know what the value of process_node.process_state is in case that the process_node.is_failed condition is True?

[danielhollas]

It is unfortunate, but the ProcessState is FINISHED in this case so there's no way to distinguish this condition based on this. Note that also the method 'is_finished' returns true if the process finished with non-zero exit status. 'is_finished_ok' method is used to really check whether there where no issues.

I am pretty sure I saw some bugs related to this in the aiidalab-qe app as well, wil laubmit PRs when I get to it.

[csadorf]

@danielhollas Sorry, looks like I introduced a bug with my suggestion: https://results.pre-commit.ci/run/github/135423835/1659623008.H_oLFNBBSs-SpAAAzru51A

[danielhollas]

@csadorf thanks, I've fixed the code and tested locally so this should be good to go.

[csadorf]

@danielhollas Thanks a lot!