The mupad ebuild contains the dependency =dev-lang/tk-8.3* which causes tcl/tk to be upgraded/downgraded on every emerge -uD world. Switching the dependency to >=dev-lang/tk-8.3* seems to correct this issue. Reproducible: Always Steps to Reproduce: 1. 2. 3.
mupad-2.5.2-r2.ebuild depends on ">=dev-lang/tk-8.3", but it is marked as "~x86" currently, you can give it a test and send a feedback here.
commiting to stable because it makes sense. And because the only changes that were made were to support amd64 which they already signed off on. I'd still really like the user to report back on success or failure.