The use of svn export in makepkg to clone a svn repo seems to break certain functionality, like "svn info" and svnversion, I've also seen the buildsystem itself being confused when building in such a cloned repo. I suggest to use cp -r for svn repos instead to work around this problem.

Steps to Reproduce:

Clone a svn repo with svn export and try to use svn info or svnversion on it.
See: https://aur.archlinux.org/packages/oscam-svn/ and try building it with and without prepare().
With prepare() (meaning that cp -r has been used) the buildprocess will output the string: OSCam ver: 1.20-unstable_svn rev: 8603 target: x86_64-unknown-linux-gnu-ssl-libusb-pcsc
With prepare() commented out (svn export used), the string is: OSCam ver: 1.20-unstable_svn rev: 0 target: x86_64-unknown-linux-gnu-ssl-libusb-pcsc
Note the strange rev number.