Compile of plsqODBC driver fails on OEL6

Hello:

I'm not sure if this is a bug, or some part of the procedure we are missing.

We are trying to compile the plsqODBC driver, refering to instructions in
https://odbc.postgresql.org/docs/unix-compilation.html, as that appears to
be the only way to install on Linux.

We are using latest 64-bit version of Postgres and plsqODBC (just
downloaded). Configure fails with:

configure: error: libpq library not found

Some clues in the config.log (attached) may be:

/usr/bin/ld: warning: libssl.so.1.0.0, needed by
/opt/PostgreSQL/9.3/lib/libpq.so, not found (try using -rpath or
-rpath-link)
/usr/bin/ld: warning: libcrypto.so.1.0.0, needed by
/opt/PostgreSQL/9.3/lib/libpq.so, not found (try using -rpath or
-rpath-link)

Yet all of the libraries are present:

[root(at)postgres9 /]# locate libpq.so
/opt/PostgreSQL/9.3/lib/libpq.so
/opt/PostgreSQL/9.3/lib/libpq.so.5
/opt/PostgreSQL/9.3/lib/libpq.so.5.6
/opt/PostgreSQL/9.3/pgAdmin3/lib/libpq.so.5

[root(at)postgres9 /]# locate libssl.so
/opt/PostgreSQL/9.3/lib/libssl.so.1.0.0
/usr/lib64/.libssl.so.1.0.0.hmac
/usr/lib64/.libssl.so.10.hmac
/usr/lib64/libssl.so.1.0.0
/usr/lib64/libssl.so.10

[root(at)postgres9 /]# locate libcrypto.so
/opt/PostgreSQL/9.3/lib/libcrypto.so.1.0.0
/usr/lib64/.libcrypto.so.1.0.0.hmac
/usr/lib64/.libcrypto.so.10.hmac
/usr/lib64/libcrypto.so.1.0.0
/usr/lib64/libcrypto.so.10

We have tried the config command with and without the --with-libpq switch,
also using lib and bin suffix, same results.

./configure --with-libpq=/opt/PostgreSQL/9.3

Latest versions just downloaded:

psqlodbc-09.03.0400.tar.gz
unixODBC-2.3.2.tar.gz
postgresql-9.3.6-1-linux-x64.run
Linux postgres9.localdomain 2.6.39-400.17.1.el6uek.x86_64 #1 SMP Fri Feb
22 18:16:18 PST 2013 x86_64 x86_64 x86_64 GNU/Linux

Thank you in advance,
Caleb.