Created attachment 787799 [details] part of build.log with error Build was failing due to docs processing error. Downgrading sphinx from ~5.0.2 to 4.5.0-r1 fixed that.
Created attachment 787802 [details] emerge --info
Created attachment 787805 [details] full build log
*** Bug 849023 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 849023 ***