man 5 hgrc implied you need to use external tools to do CRLF translation.
This is no longer true; win32text provides a much better in-process alternative.
# should print nothing
# should fail
abort: path 'b/x' is inside repo 'b'
abort: path 'b/x' is inside repo 'b'
# should fail
abort: path 'b/x' is inside repo 'b'
# should arguably print nothing
# should fail
abort: path 'b/a' is inside repo 'b'