[MonoDevelop] MonoDevelop not picking up .pc files from /usr/local?

[IBBoard]

I'm trying to build the Mercurial plugin that was just mentioned in the 
group. I'm running a Git build of MD, which is installed to /usr/local. 
This seems to be breaking the way MD recognises package locations.

If I run pkg-config then it lists MonoDevelop and has found the files 
like "/usr/local/lib/pkgconfig/monodevelop.pc", but if I open the 
Mercurial project then all of the MD references say "Assembly not 
available for Mono / .Net [insert version]". If I edit the references 
then there is no reference to MD packages in the list.

If I run "PKG_CONFIG_PATH=/usr/local/lib/pkgconfig monodevelop" then MD 
picks up the paths appropriately and everything is detected and 
referenced appropriately.

Am I doing something wrong, or is this a bug that needs reporting?

Thanks.