I had a seemingly benign, yet annoying error that I got around to fixing the other day. The short version is that every time I opened a terminal I got the following error:

error: could not open file /var/lib/pacman/local/bcc-1.06.95-2/dsce: No such file or directory

Trying to upgrade, or downgrade, the package results in the same error.

Easy enough to fix, simply:

1) Boot from an live USB

2) Mount and chroot into your root filesystem

3) Backup necessary setting if needed (e.g. # mv /etc/cups > /etc/cups.bk)

4) Uninstall the problem package (# pacman -Rns <package>)

5) Reinstall the package (# pacman -S <package>)

6) Restore prior settings (e.g. # rm -r /etc/cups && mv /etc/cups.bk /etc/cups)

That did the trick for me. Feel free to comment if you find other solution, or similar erorrs.