When using non-standard include/lib paths GnuTLS is successfully located by pkg-config but it fails to build. I believe this is due to GnuTLS being split into multiple libraries which need to be located.
Here is an example build showing how it fails to build with a non-standard path but succeeds with a standard path: http://pastie.org/private/a4rvnnltami9laacstdra.
That pastebin shows me this:
Change this error message for exceptions thrown outside of an action (like in Dispatcher setups or broken Ruby code) in public/500.html
You can paste the entire thing here inside code tags and it wont mess with the formatting.
One can get the correct include path using the libgcrypt-config --cflags command. Linker flags are available using --libs. pkg-config isn't supported by libgcrypt, unfortunately.
Fix m_ssl_gnutls when using non-standard include/lib paths.
This fixes #315.