python pip install psycopg2 install error

Question

I did a simple pip install psycopg2 on mac system. It installed fine, but when I try to use psycopg2 I get the error:

Reason: Incompatible libra         


        

Answer 1

I ran into a similar problem after upgrading to Mountain Lion.

Instead of copying libssl.* files per Slack's suggestion, make sure that /usr/lib/libssl.dylib is actually a soft link to the most up-to-date version of the library.

E.g., on my machine, ls -l /usr/lib/libssl* gives:

lrwxr-xr-x  1 root  wheel    46B Jun 27 15:24 /usr/lib/libssl.1.0.0.dylib -> /Library/PostgreSQL/9.1/lib/libssl.1.0.0.dylib
lrwxr-xr-x  1 root  wheel    27B Jul 30 10:31 /usr/lib/libssl.dylib -> /usr/lib/libssl.1.0.0.dylib

If libssl.dylib doesn't link to the version that the error version mentions, make sure you have that version of the library, and then make sure /usr/lib/libssl.dylib points to it, and not an older version.

If the link doesn't exist, create it like so

sudo ln -s library_to_link_to link_to_create

using, of course, the proper locations for your machine. For me, this turned out to be:

sudo ln -s /usr/lib/libssl.1.0.0.dylib /usr/lib/libssl.dylib

Edit:

It seems like some are having trouble with part of my solution. Namely, deleting these important libraries even temporarily causes problems with the operating system.

Per Purrell's answer, make sure you include the -fs flags when you use the ln command, which helps ensure that the libraries don't go missing for a short period of time. E.g.,

sudo ln -fs /usr/lib/libssl.1.0.0.dylib /usr/lib/libssl.dylib
sudo ln -fs /usr/lib/libcrypto.1.0.0.dylib /usr/lib/libcrypto.dylib

Answer 2

I had similar problem on my Mac OS High Sierra.

ImportError: dlopen(/Users/chicha/Projects/CTMR/sample_registration/romans_env/lib/python3.7/site-packages/psycopg2/_psycopg.cpython-37m-darwin.so, 2): Library not loaded: /opt/local/lib/libssl.1.0.0.dylib

But after "pip install postgres" it's work fine. According to pip show - "postgres is a high-value abstraction over psycopg2". While installing it's also installed psycopg2-binary and psycopg2-pool. So, all together they have repaired the situation somehow.

Answer 3

On OSX 10.11, El Capitan, solution with replacing symlinks reported Operation not permitted. Solution that worked for me was using brew and setting up DYLD_LIBRARY_PATH. So:

brew install openssl

Find where openssl brew libs are located (brew --prefix openssl can help), start searching from directory /usr/local/Cellar/openssl. In my case it is in /usr/local/Cellar/openssl/1.0.2d_1/lib

Finally set up DYLD_LIBRARY_PATH, i.e. add a line like this into .bash_profile :

# replace location of lib files with folder name you found in previous step
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/usr/local/Cellar/openssl/1.0.2d_1/lib

UPDATE: More generic/better alternatives are (thanks to @dfrankow):

• to use brew to find openssl location (a note, brew can be slow): DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:$(brew --prefix openssl)/lib
• for development purposes maybe it is better to use DYLD_FALLBACK_LIBRARY_PATH instead - check this

Restart shell, or just source ~/.bash_profile, reinstall psycopg2:

pip uninstall psycopg2
pip install psycopg2

and test if it works:

$ python -c"import psycopg2  ;   print('psycopg2 is now ok')"

Answer 4

Worked for me:

env LDFLAGS='-L/usr/local/lib -L/usr/local/opt/openssl/lib
-L/usr/local/opt/readline/lib' pip install psycopg2

Source: https://code-examples.net/en/q/93ae48