Only for MRI ruby? Doesnt work with Jruby

[aditya-sanghi]

find_executable: checking for pg_config... -------------------- yes

---

" -o conftest -I/include/universal-java1.8 -I/usr/local/Cellar/rbenv/1.1.0/versions/jruby-9.1.6.0/lib/ruby/include/ruby/backward -I/usr/local/Cellar/rbenv/1.1.0/versions/jruby-9.1.6.0/lib/ruby/include -I. -I/usr/local/Cellar/postgresql/9.6.1/include -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE -fPIC -DTARGET_RT_MAC_CFM=0 -fno-omit-frame-pointer -fno-strict-aliasing -fexceptions conftest.c -L. -L/usr/local/Cellar/rbenv/1.1.0/versions/jruby-9.1.6.0/lib -L/usr/local/lib -arch x86_64 "
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: #include <ruby.h>
4: int main(int argc, char *argv)
5: {
6: return 0;
7: }
/ end */

[diogob]

Closing as duplicate of #15
I'll reopen that issue as a possible enhancement.