(Originally accidentally sent this to guile-devel@gnu.org ... sorry!)

Hiya,

I pushed guile2.2-gdbm because it was just a couple of lines and it
seemed to work and didn't affect anything.  I made a mistake though that
I didn't realize until I ran
"guix environment --ad-hoc guile-next guile2.2-gdbm-ffi --pure".
The trivial-build-system in guile-gdbm-ffi dumps the built module into
(string-append out "/share/guile/site/2.0") ... oops!  Before I ran
--pure, the 2.0 directory was on my load path, and thus I didn't bump
into the error.  (Maybe I should have asked for review anyway...)

I'm trying to think of how to fix this.  I have a very kludgy solution
attached.  I don't feel great about it but I don't know how to signal to
the builder whether it's using guile 2.2 or 2.0 otherwise.  Thoughts?