Since Go 1.19 (commit ae3d890) '' is unconditionally transformed to “ or ”. This means my comment:

// lexMultilineRawString consumes a raw string. Nothing can be escaped in such
// a string. It assumes that the beginning ''' has already been consumed and
// ignored.

Now becomes:

// lexMultilineRawString consumes a raw string. Nothing can be escaped in such
// a string. It assumes that the beginning ”' has already been consumed and
// ignored.

There are some other cases, especially when parsing things, where one might reasonably want to type '' inside a regular (non-codeblock) comment.

Looking at go/doc/comment/parse.go, there is no way to escape this behaviour, and I don't really see an obvious non-ugly way to write that comment.