Many poudriere builds get stuck in lib-depends and run-depends phases and never succeed

From: Yuri <yuri_at_FreeBSD.org>
Date: Mon, 10 Oct 2022 17:56:33 UTC
Every once in a while when many builds happen to be all in lib-depends 
and run-depends phases in poudriere - they get stuck and later all fail 
together.

All failures look like in the log below. It's looks like many 'pkg 
install llvmNN' processes for different builds compete with each other 
and don't progress.


Does anybody else have such problem? What could be a solution?



Thanks,

Yuri





---begin log---

===>   qcsxcad-0.6.2.9_2 depends on shared library: libQt5Gui.so - not found
===>   Installing existing package /packages/All/qt5-gui-5.15.5p165.pkg
[13amd64-local-workstation-job-03] Installing qt5-gui-5.15.5p165...
[13amd64-local-workstation-job-03] `-- Installing mesa-dri-21.3.8...
[13amd64-local-workstation-job-03] |   `-- Installing libXv-1.0.11_2,1...
[13amd64-local-workstation-job-03] |   `-- Extracting libXv-1.0.11_2,1: 
.......... done
[13amd64-local-workstation-job-03] |   `-- Installing libXvMC-1.0.12...
[13amd64-local-workstation-job-03] |   `-- Extracting libXvMC-1.0.12: 
.......... done
[13amd64-local-workstation-job-03] |   `-- Installing 
libunwind-20211201_1...
[13amd64-local-workstation-job-03] |   `-- Extracting 
libunwind-20211201_1: .......... done
[13amd64-local-workstation-job-03] |   `-- Installing libxshmfence-1.3_1...
[13amd64-local-workstation-job-03] |   `-- Extracting 
libxshmfence-1.3_1: ......... done
[13amd64-local-workstation-job-03] |   `-- Installing llvm13-13.0.1_3...
[13amd64-local-workstation-job-03] |   | `-- Installing lua53-5.3.6...
[13amd64-local-workstation-job-03] |   | `-- Extracting lua53-5.3.6: 
.......... done
[13amd64-local-workstation-job-03] |   `-- Extracting llvm13-13.0.1_3: .....
Failed to install the following 1 package(s): 
/packages/All/qt5-gui-5.15.5p165.pkg
*** Error code 1

---end log---