unison/unison-src/transcripts/dont-upgrade-refs-that-exist-in-old.md

If foo#old exists in old, and foo#new exists in new, you might think upgrade old new would rewrite references to #old with references to #new. And it will... !!unless!! #old still exists in new.

foo/main> builtins.merge lib.builtin

lib.old.foo = 18
lib.new.other = 18
lib.new.foo = 19
mything = lib.old.foo + lib.old.foo

foo/main> add
foo/main> upgrade old new
foo/main> view mything