The mysql PKGBUILD is a real mess. The .14 instead of .so.14 bug gets solved with a hacky workaround that needs to be changed with every .so bump. This is a known bug, since it affects some other packages as well: it's because of the libtool that is used by some developers. forcing libtoolize to generate new files fixes the bug and does away with the move and symlink hacks.

Further, the copy & sed operations can be simplified: since version 4.x sed supports the -i option, that modifies files in place. I'll attach a fixed PKGBUILD. I didn't look at the fPIC bug reported, but I think it's good to fix this one also (it's actually some kind of bug in mysql itself, all shared libs should be compiled with -fPIC)