This is an auto-filled bug because app-misc/tmuxp fails tests (hang).
The issue was originally discovered on amd64, but it may be reproducible on other arches as well.
If you think that a different summary clarifies the issue better, feel free to change it.
Attached build log and emerge --info.
I had to kill the process.
Created attachment 637884 [details]
build log and emerge --info
tinderbox_musl has reproduced this issue with version 1.9.4 - Updating summary.