There are numerous build timeouts on powerpc64 that happen in the cluster (for gcc-arm-embedded, libreoffice and various llvm versions).
I already reported them via email to portmgr, but either they didn't receive those emails or for some other reason didn't change timeouts.
I am really puzzled about that. 30h is already very very long, the solution is probably to request fresh new hardware for the cluster.
(In reply to Baptiste Daroussin from comment #1)
The hardware is AFAIK Tyan machines with POWER8, so not that slow. I think it's more about ppc64 itself being slower than amd64 on FreeBSD (the situation is improving thanks to ongoing work by some developers).
AFAIK the Foundation also bought some Talos systems, but I don't know when they will be ready for work in the cluster (sbruno probably knows more).
Anyway, those packages build in Poudriere on powerpc64 on my own server, but I can't give you the time that is necessary, because I have ALLOW_MAKE_JOBS=yes set.
Seems fine for now, looks like setting 40h was a right choice (rust and paraview took more than 30h, they would have failed with old settings).