When running an unnamed macro in ROOT6, if one includes an opening parenthesis in a block comment and not a closing one, cling issues an error.
When run in 6.02/05, it causes the error:
This runs fine in ROOT5 however (tested on 5.34/30).
Note that cling doesn't have an issue with the closing parenthesis [i.e. :) ], nor does it mind a solo "(" in a single line comment, e.g.