Install psycopg2 failed on macOS

Question

I have installed PostgreSQL by brew on macOS:

brew install postgresql

Tried these commands, all failed:

• pipenv install psycopg2
• pip install psycopg2

Error:

...
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -DPSYCOPG_VERSION=2.8.4 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120001 -DHAVE_LO64=1 -I/Users/user0/.pyenv/versions/3.8.0/include/python3.8 -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/adapter_qstring.c -o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_qstring.o
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -DPSYCOPG_VERSION=2.8.4 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120001 -DHAVE_LO64=1 -I/Users/user0/.pyenv/versions/3.8.0/include/python3.8 -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/microprotocols.c -o build/temp.macosx-10.14-x86_64-3.8/psycopg/microprotocols.o
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -DPSYCOPG_VERSION=2.8.4 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120001 -DHAVE_LO64=1 -I/Users/user0/.pyenv/versions/3.8.0/include/python3.8 -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/microprotocols_proto.c -o build/temp.macosx-10.14-x86_64-3.8/psycopg/microprotocols_proto.o
  In file included from psycopg/microprotocols_proto.c:27:
  In file included from ./psycopg/psycopg.h:37:
  ./psycopg/config.h:81:13: warning: unused function 'Dprintf' [-Wunused-function]
  static void Dprintf(const char *fmt, ...) {}
              ^
  1 warning generated.
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -I/Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/usr/include -DPSYCOPG_VERSION=2.8.4 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120001 -DHAVE_LO64=1 -I/Users/user0/.pyenv/versions/3.8.0/include/python3.8 -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/typecast.c -o build/temp.macosx-10.14-x86_64-3.8/psycopg/typecast.o
  clang -bundle -undefined dynamic_lookup -L/usr/local/opt/readline/lib -L/usr/local/opt/readline/lib -L/Users/user0/.pyenv/versions/3.8.0/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/readline/lib -L/Users/user0/.pyenv/versions/3.8.0/lib build/temp.macosx-10.14-x86_64-3.8/psycopg/psycopgmodule.o build/temp.macosx-10.14-x86_64-3.8/psycopg/green.o build/temp.macosx-10.14-x86_64-3.8/psycopg/pqpath.o build/temp.macosx-10.14-x86_64-3.8/psycopg/utils.o build/temp.macosx-10.14-x86_64-3.8/psycopg/bytes_format.o build/temp.macosx-10.14-x86_64-3.8/psycopg/libpq_support.o build/temp.macosx-10.14-x86_64-3.8/psycopg/win32_support.o build/temp.macosx-10.14-x86_64-3.8/psycopg/solaris_support.o build/temp.macosx-10.14-x86_64-3.8/psycopg/connection_int.o build/temp.macosx-10.14-x86_64-3.8/psycopg/connection_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/cursor_int.o build/temp.macosx-10.14-x86_64-3.8/psycopg/cursor_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/column_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/replication_connection_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/replication_cursor_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/replication_message_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/diagnostics_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/error_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/conninfo_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/lobject_int.o build/temp.macosx-10.14-x86_64-3.8/psycopg/lobject_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/notify_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/xid_type.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_asis.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_binary.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_datetime.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_list.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_pboolean.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_pdecimal.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_pint.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_pfloat.o build/temp.macosx-10.14-x86_64-3.8/psycopg/adapter_qstring.o build/temp.macosx-10.14-x86_64-3.8/psycopg/microprotocols.o build/temp.macosx-10.14-x86_64-3.8/psycopg/microprotocols_proto.o build/temp.macosx-10.14-x86_64-3.8/psycopg/typecast.o -L/usr/local/lib -lpq -lssl -lcrypto -o build/lib.macosx-10.14-x86_64-3.8/psycopg2/_psycopg.cpython-38-darwin.so
  ld: library not found for -lssl
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  error: command 'clang' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for psycopg2

Also, setting this to shell and then reloading:

export PATH=/usr/local/Cellar/postgresql/12.1/bin:$PATH

doesn't work either.

Answer 1

• Try downgrade version of your Python3
• Try use pip3

I solved this problem with that method

Answer 2

First thing first, you need to verify that openssl is installed and correctly linked:

brew install openssl
export LDFLAGS="-L/usr/local/opt/openssl/lib"
export CPPFLAGS="-I/usr/local/opt/openssl/include"

Now, if using python 3.8 means python executable is bound to python 3.8, you may want to try the following workarounds:

• Workaround #1: Install specifying the interpreter

python -m pip --no-cache install psycopg2

Just to be sure that the version of pip you're calling is indeed the one which is bound to your Python version.

If it still doesn't work, you might be running into this issue in that case you can downgrade your version of Python and try the above command again

• Workaround #2: Install from source.

First, you need to download the source code hosted on PyPI and run the commands:

tar -xf psycopg2-2.8.4.tar.gz && cd psycopg2-2.8.4 # extract the file
python setup.py build
sudo python setup.py install

Answer 3

The best solution to go to in this case is to install the binary package

  pip install psycopg2-binary

After it, you could still try to re-install an older version of the psycopg2 package like this. This should work if you don't need necessarily the last version.

  pip install psycopg2==2.7.5