Re: /usr/bin/ld: cannot find -lpq

Tena Sakai <tsakai(at)gallo(dot)ucsf(dot)edu> writes:
> ... I just tried recompiling it on that machine and it compiles without a
> complaint. I now need to re-compile it on a Intel 32-bit machine running
> centOS. When I issue the same command on the centOS machine, I get
> complaint:
> /usr/bin/ld: cannot find -lpq
> collect2: ld returned 1 exit status

> I thought that this meant that the shared library named libpq.so.bla
> is missing. But to my surprise, I find libpq.so.4.1 in /usr/lib
> directory. (There is also a symbolic link libpq.so.4 pointing at
> libpq.so.4.1 in the same place.)

What you need to build a program relying on a shared library is
libfoo.so --- not libfoo.so.n, which is what is used at runtime.
Normally, libfoo.so is a symlink provided by the -devel package
for the library. In short, then, your problem is that you don't
have postgresql-devel installed. What seems odd is that you got
this far, because postgresql-devel also carries the header files
you need for compiling callers of libpq (ie, /usr/include/libpq-fe.h).
I'd have expected a failure mentioning lack of libpq-fe.h. Seems
like you must have some sort of broken partial installation on
that machine.

regards, tom lane