Arch Linux

When installing package pacman is overwriting directories' and files' permissions.
This can lead to bad situations (I had one in past days) when PKGBUILD produces directory tree with wrorng permissions.
This often happen when creating packages for software that comes in rpm or binary form.
For example rpms have all directories readable and browsable only for root! So when user forgets to do find $startdir/pkg -type d -exec chmod 755 {} \; after unpacking rpm with rpmextract bad things may happen. For example I broke my system twice in past days because I forget to chmod +x /etc and /usr dirs for one rpm-based package (my fault).

So, to avoid such things for home-made packages or packages installed with AUR autoinstalling tools (yaourt, aurbuild, qpkg, aur-install) it will be nice to have the following feature(s):
1) pacman should check permissions for all files and (especially) directories that are overwritten by package and warn user if there are some differences. I know this may be hard to implament, I don't know if libarchive have something that makes this support easier. And I don't know how this will affect package installing speed.
AND/ORr
2) makepkg should make sure that $startdir/pkg/* directories have correct parmissions set. This is much easier IMO, and it doesn't costs much to implement.
AND
3) namcap should check for such issues too. Currently it show warnings about "directory has no word readable bit set" and wrong owner/group, but for _executable_ bit for directories.