This is an auto-filed bug because dev-ruby/actionpack-action_caching fails tests. 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. NOTE: If you need further logs, feel free to ask.
Created attachment 640118 [details] build.log build log and emerge --info
lto_tinderbox has reproduced this issue with version 1.2.2 - Updating summary.
Hard to see how this can happen. rails-html-sanitizer is installed and that has a runtime dependency on dev-ruby/loofah. Is loofah installed and not found, or not installed?