The reason is that fakeroot can't read files that have restrictive
perms and you'd have to change them before the src installation, and
restoring them at binpkg pre-installation.
I prefer to avoid all this and build the pkg with appropiate perms.
--HG--
extra : convert_revision : 8a5086049ab575962913eda0cb2ace0c211b97f1
Juan RP