In an unrelated change I fixed the import line in "internal/lsp/testdata/implementation/implementation.go" and that made the below test start flaking:

type U interface {
	U() //@mark(IntU, "U"),implementations("U", ImpU),
}

It fails when "implementation" package's "Foo" type wins the dedupe check. implementation.Foo's "U" method lies in another package, which breaks the code that tries to look up the methods file/position. It works if "other.Foo" wins since "U" is implemented in the "other" package.

We need to fix the bug and then re-enable the test.