This is an auto-filled bug because dev-python/setproctitle calls commands that do not exist. The issue was originally discovered on arm64, 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.
Created attachment 634708 [details] build.log build log and emerge --info
This was fixed via: commit 3d915b9a36c4158c98b12f0c4da7a25dde8034b0 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: 2020-06-12 16:58:59 +0200 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: 2020-06-12 17:40:16 +0200 dev-python/setproctitle: Port to py3.9 Signed-off-by: Michał Górny <mgorny@gentoo.org>