What did you do?

The transition logic attempts to keep the Jira Issue State in sync with the Alert State.

Reopen Transition: If an alert starts Firing again, but the existing Jira issue is already Closed/Done, Alertmanager tries to "transition" the issue back to Open/In Progress.
Resolve Transition: If an alert is Resolved, Alertmanager tries to "transition" the issue to Closed/Done.

I configured the Jira receiver but left reopen_transition (or resolve_transition) empty because I do not want Alertmanager to change the status of existing issues.

What did you expect to see?

I expected Alertmanager to update the issue fields (Summary/Description) but skip the status transition if the configuration string is empty.

What did you see instead? Under which circumstances?

Alertmanager attempted to perform a transition using an empty string as the transition name, resulting in an error log:
can't find transition for issue

System information

No response

Alertmanager version

Alertmanager configuration file

Prometheus version

Prometheus configuration file

Logs