Let's say that I'd like to replace python with python3.8 in all the tests within a port. I cannot do it with BINARY_ALIAS, because it will fail as BINARY_ALIAS is processed way before test dependencies are extracted.
A commit references this bug: Author: 0mp Date: Tue Nov 3 12:39:33 UTC 2020 New revision: 54673 URL: https://svnweb.freebsd.org/changeset/doc/54673 Log: Explain why BINARY_ALIASES cannot be used for programs from TEST_DEPENDS PR: 247637 Changes: head/en_US.ISO8859-1/books/porters-handbook/makefiles/chapter.xml