https://bugs.winehq.org/show_bug.cgi?id=39490
--- Comment #8 from kolAflash kolAflash@kolahilft.de --- (In reply to Sebastian Lackner from comment #6)
There was indeed a mistake in that commit, which was fixed in: http://source.winehq.org/git/wine.git/commit/d774442e8
Does backporting this patch on top of 1.7.53 fix your issue?
Just tested commit d774442e8 and the commit before it. Looks like d774442e8 fixes the problem!
Alternatively adding a drive Z: to / also fixes it.
Thanks for the help!