Coupla problems - probably not new, but since yours seems to be the active fork... :) I'm building on OS X 10.6.8, homebrew-installed Postgresql 9.0.4.

1. The makefiles hardcode /opt/local. Could you just have them use the PATH for include/lib, and /usr/bin/env to find ginstall?
2. make test fails because LANCOMPILER is no longer valid.
3. Once I remove the lancompiler argument, make test under Ruby 1.8.7 crashes Postgres: https://gist.github.com/1260777
4. If I rebuild under 1.9.2, it fails to create the language; I don't see this output (or any sign of the 'create') in test.out, but if I do it manually, it complains about _Init_stack, and there was much unhappiness in mkmf.log: https://gist.github.com/1260784

Any ideas? I'm happy to troubleshoot.

Jay;

1. not seeing the /opt/local hardcoding in the code.
2. 'lancompiler' was only valid in postgres 7, and even there, it was not used. Took it out in commit '5818d6'
3. Only test suite that currently passes for postgres 9.1.1 is conv_network.
   This is on OS X 10.6.8 and ruby 1.8.7.
4. On Ubuntu, having problems linking the shared library:
   gcc -shared -o plruby.so plruby.o plplan.o plpl.o pltrans.o -L. -L/usr/local/lib -Wl,-R/usr/local/lib -L. -rdynamic -Wl,-export-dynamic -lruby-static -lpq -lrt -ldl -lcrypt -lm -lc
   /usr/bin/ld: /usr/local/lib/libruby-static.a(array.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
   /usr/local/lib/libruby-static.a: could not read symbols: Bad value
   collect2: ld returned 1 exit status
   make[1]: *** [plruby.so] Error 1