Problems using psycopg2 on Mac OS (Yosemite)

48
votes

Currently I am installing psycopg2 for work within eclipse with python.

I am finding a lot of problems:

  1. The first problem sudo pip3.4 install psycopg2 is not working and it is showing the following message

Error: pg_config executable not found.

FIXED WITH:export PATH=/Library/PostgreSQL/9.4/bin/:"$PATH”

  1. When I import psycopg2 in my project i obtein:

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so Library libssl.1.0.0.dylib Library libcrypto.1.0.0.dylib

FIXED WITH: sudo ln -s /Library/PostgreSQL/9.4/lib/libssl.1.0.0.dylib /usr/lib sudo ln -s /Library/PostgreSQL/9.4/lib/libcrypto.1.0.0.dylib /usr/lib

  1. Now I am obtaining:

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so, 2): Symbol not found: _lo_lseek64 Referenced from: /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so Expected in: /usr/lib/libpq.5.dylib in /Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/psycopg2/_psycopg.so

Can you help me?

8
pythoneclipsemacospostgresqlpsycopg2

8 Answers

77
votes

You need to replace the /usr/lib/libpq.5.dylib library because its version is too old.
Here's my solution to this problem:

$ sudo mv /usr/lib/libpq.5.dylib /usr/lib/libpq.5.dylib.old  
$ sudo ln -s /Library/PostgreSQL/9.4/lib/libpq.5.dylib /usr/lib
28
votes

If you are using PostgresApp, you need to run the following two commands:

sudo mv /usr/lib/libpq.5.dylib /usr/lib/libpq.5.dylib.old
sudo ln -s /Applications/Postgres.app/Contents/Versions/9.4/lib/libpq.5.dylib /usr/lib
11
votes

I was able to fix this on my Mac (running Catalina, 10.15.3) by using psycopg2-binary rather than psycopg2.

pip3 uninstall psycopg2 pip3 install psycopg2-binary

4
votes

I am using yosemite, postgres.app & django. this got psycopg2 to load properly for me but the one difference was that my libpq.5.dylib file is in /Applications/Postgres.app/Contents/Versions/9.4/lib.

thus my second line was sudo ln -s /Applications/Postgres.app/Contents/Versions/9.4/lib/libpq.5.dylib /usr/lib

4
votes

Here's a fix that worked for me on El Capitan that doesn't require restarting to work around the OS X El Capitan System Integrity Protection (SIP):

brew unlink postgresql && brew link postgresql
brew link --overwrite postgresql

H/T Farhan Ahmad

2
votes

For those of you on El Capitan who can't use @KungFuLucky7's answer - I used the following to fix the issue (Adjust paths to match yours where required).

sudo install_name_tool -change libpq.5.dylib /Library/PostgreSQL/9.5/lib/libpq.5.dylib /usr/local/lib/python2.7/site-packages/psycopg2/_psycopg.so
1
votes

In El Capitan, I used the same solution as @Forbze but 2 more commands as follows.

sudo install_name_tool -change libpq.5.dylib /Library/PostgreSQL/9.3/lib/libpq.5.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so
sudo install_name_tool -change libssl.1.0.0.dylib /Library/PostgreSQL/9.3/lib/libssl.1.0.0.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so
sudo install_name_tool -change libcrypto.1.0.0.dylib /Library/PostgreSQL/9.3/lib/libcrypto.1.0.0.dylib  /Library/Python/2.7/site-packages/psycopg2/_psycopg.so

It works perfectly!

0
votes

well, I'd like to give my solution, the problem is related with the version of c. So, I just typed:

CFLAGS='-std=c99' pip install psycopg2==2.6.1