[CMake] CPack Bundle Generator easily hits hdiutil MNAMELEN limit

[Mike Arthur]

From the hdiutil manpage:
-mountroot path	mount volumes in path instead of in /Volumes.  path must 
exist.  Note that mountpoint paths must be less than MNAMELEN characters (90 
as of this writing).

This limit is easily hit by the mounting of the temporary dmg (tmp.dmg) in the 
Bundle Generator and causes it to fail.

May I suggest that, instead of mounting into ./_CPack_Packages/OSX-
Universal/Bundle/mnt/ instead /tmp/cpackmnt/ is used instead or the mountpoint 
parameter omitted and the Volumes mountpoint is used instead?

I can write a patch if necessary but it should be a trivial fix (if agreed).
-- 
Cheers,
Mike Arthur
http://mikearthur.co.uk/