This is an auto-filled bug because dev-lang/spidermonkey fails to compile on s390. Feel free to adjust the summary to clarify the exact issue. Attached build log and emerge --info
Created attachment 619712 [details] spidermonkey-60.5.2_p0-r2:20200315-115944.log.bz2 build log
Created attachment 619714 [details] emerge --info emerge --info
The affected ebuild has been removed.