This first arose in bug 876935 . Upstream discovered `expr` in https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=a2cf51894d2a3dc05823e37cdf15252b1cc087e6 which landed in version 6.0.2 in late 2022. bc also remains no longer needed as of the upstream 6.9.1 and seems unlikely to return. { Indeed, perhaps upstream will discover $(()) shell arithmetic for the simple `TROFF_LINE_LENGTH := $(shell $(EXPR) $(MANWIDTH) - 2)` calculation? Admittedly, makefile quoting probably makes such annoying. } In any event, cognizant of bug 930798, this unneeded dep should be dropped from the ebuild as part of bumping.