Summary and Info:
when makepkg is ran with -ic switches, and the installation of built package failed, it leaves pkg and src directories on the disk. I think this is not good, because we have build process finished good, and met the problem with the package manager itself. I did not make a patch, because it will probably require to rewrite a big part of code. :) But the simple solution that comes to my mind is to remove the `$EXIT_CODE -eq 0` check from the clean_up function, since I don't need build files on my disk if I explicitly gave an -c option.

Steps to Reproduce:
1. run pacman -Syu and don't confirm anything
2. run makepkg -ic for some PKGBUILD

Example:
[onestep@onestep-box xcb-proto]$ makepkg -ic
==> Making package: xcb-proto 1.4-1 x86_64 (Sun Feb 22 13:08:18 EET 2009)
...
==> Finished making: xcb-proto 1.4-1 x86_64 (Sun Feb 22 13:08:25 EET 2009)
==> Installing package xcb-proto with pacman -U...
error: failed to init transaction (unable to lock database)
if you're sure a package manager is not already
running, you can remove /var/lib/pacman/db.lck
[onestep@onestep-box xcb-proto]$ ls
PKGBUILD pkg src