rails - postgres error: Reason: Incompatible library version: libpq.5.dylib requires version 1.0.0 or later,

Question

I am stuck with the setup of Ruby (1.9.3), Rails and Postgres (9.0.8) on my Mac (10.6.8). Everytime when I run rails console I get the following error:

Answer 1

I ran into this also, but was able to fix it following the instructions on python pip install psycopg2 install error.

First, make sure you have the most recent version of OpenSSL installed:

MacBook Pro:~> openssl version -a
OpenSSL 1.0.0c 2 Dec 2010
built on: Mon Jan  3 17:26:21 PST 2011
platform: darwin64-x86_64-cc
options:  bn(64,64) rc4(ptr,char) des(idx,cisc,16,int) idea(int) blowfish(idx) 
compiler: /usr/bin/gcc-4.2 -fPIC -fno-common -DOPENSSL_PIC -DZLIB -DOPENSSL_THREADS -D_REENTRANT -DDSO_DLFCN -DHAVE_DLFCN_H -arch x86_64 -O3 -DL_ENDIAN -DMD32_REG_T=int -Wall
OPENSSLDIR: "/opt/local/etc/openssl"

...and note the OPENSSLDIR. On my system, it's in /opt/local/, because I installed it via MacPorts. I just needed to update the symlinks in /usr/lib/ for libssl.dylib and libcrypto.dylib so that they pointed to the correct versions in /opt/local/lib instead of the old version in usr/lib:

MacBook Pro:~> ls -la /usr/lib/libssl.dylib 
lrwxr-xr-x  1 root  wheel  33 Aug 17 12:25 /usr/lib/libssl.dylib -> /opt/local/lib/libssl.1.0.0.dylib
MacBook Pro:~> ls -la /usr/lib/libcrypto.dylib 
lrwxr-xr-x  1 root  wheel  36 Aug 17 12:28 /usr/lib/libcrypto.dylib -> /opt/local/lib/libcrypto.1.0.0.dylib

You can create the links by using the ln command:

sudo ln -s /path/to/postgres/install/lib/libcrypto.dylib /usr/lib/libcrypto.dylib
sudo ln -s /path/to/postgres/install/lib/libssl.dylib /usr/lib/libssl.dylib