GPGME install requirements

[Roberto Aguilar]

Hello,

I have been struggling to get an OS X application to use GPGME.  Per
the instructions I found on the Internet, I built and installed
libassuan, libgpg-error, and gpgme.  Just those three fail with the
message "invalid crypto engine".

Further searching suggested installing gpg2, which I did from source,
but then had trouble with pinentry.

As a last ditch effort, I installed the GPGTools package [1], rebuilt
gpgme, and now the program that uses gpgme works.

>From here I'm trying to deduce what libraries from within the GPGTools
package is gpgme requiring.

I've done some cursory tests and confirm that if the binary gpg2 is
not available GPGME does not work.  Does gpgme shell out to gpg2
internally?

Thanks for the help!
-Roberto.

[1] http://gpgtools.org/