错误：psycopg2 的构建轮失败

Question

I've been trying to connect my databse to pgadmin4. I connected it successfully but now my heroku app returns internal server error. In order to debug this I do heroku logs -t and it returns ImportError: No module named psycopg2 . So I then try to do pip install psycopg2 but I get the following error:

Collecting psycopg2
  Using cached psycopg2-2.8.5.tar.gz (380 kB)
Building wheels for collected packages: psycopg2
  Building wheel for psycopg2 (setup.py) ... error
  ERROR: Command errored out with exit status 1:
   command: /Users/Documents/venv/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"'; __file__='"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-wheel-z2s31ha_
       cwd: /private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/
  Complete output (42 lines):
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.macosx-10.15-x86_64-3.7
  creating build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/_json.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/extras.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/compat.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/errorcodes.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/tz.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/_range.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/_ipaddress.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/_lru_cache.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/__init__.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/extensions.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/errors.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/sql.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  copying lib/pool.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
  running build_ext
  building 'psycopg2._psycopg' extension
  creating build/temp.macosx-10.15-x86_64-3.7
  creating build/temp.macosx-10.15-x86_64-3.7/psycopg
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DPSYCOPG_VERSION=2.8.5 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120002 -DHAVE_LO64=1 -I/usr/local/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/sqlite/include -I/Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include -I/usr/local/opt/python/Frameworks/Python.framework/Versions/3.7/include/python3.7m -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/psycopgmodule.c -o build/temp.macosx-10.15-x86_64-3.7/psycopg/psycopgmodule.o
  In file included from psycopg/psycopgmodule.c:28:
  In file included from ./psycopg/psycopg.h:35:
  In file included from /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include/Python.h:8:
  /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include/pyconfig.h:59:10: fatal error: 'io.h' file not found
  #include <io.h>
           ^~~~~~
  1 error generated.

  It appears you are missing some prerequisite to build the package from source.

  You may install a binary package by installing 'psycopg2-binary' from PyPI.
  If you want to install psycopg2 from source, please install the packages
  required for the build and try again.

  For further information please check the 'doc/src/install.rst' file (also at
  <https://www.psycopg.org/docs/install.html>).

  error: command 'clang' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for psycopg2
  Running setup.py clean for psycopg2
Failed to build psycopg2
Installing collected packages: psycopg2
    Running setup.py install for psycopg2 ... error
    ERROR: Command errored out with exit status 1:
     command: /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"'; __file__='"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-record-3cminrp4/install-record.txt --single-version-externally-managed --compile --install-headers /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include/site/python3.7/psycopg2
         cwd: /private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/
    Complete output (42 lines):
    running install
    running build
    running build_py
    creating build
    creating build/lib.macosx-10.15-x86_64-3.7
    creating build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/_json.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/extras.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/compat.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/errorcodes.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/tz.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/_range.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/_ipaddress.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/_lru_cache.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/__init__.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/extensions.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/errors.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/sql.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    copying lib/pool.py -> build/lib.macosx-10.15-x86_64-3.7/psycopg2
    running build_ext
    building 'psycopg2._psycopg' extension
    creating build/temp.macosx-10.15-x86_64-3.7
    creating build/temp.macosx-10.15-x86_64-3.7/psycopg
    clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -DPSYCOPG_VERSION=2.8.5 (dt dec pq3 ext lo64) -DPG_VERSION_NUM=120002 -DHAVE_LO64=1 -I/usr/local/include -I/usr/local/opt/openssl@1.1/include -I/usr/local/opt/sqlite/include -I/Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include -I/usr/local/opt/python/Frameworks/Python.framework/Versions/3.7/include/python3.7m -I. -I/usr/local/include -I/usr/local/include/postgresql/server -c psycopg/psycopgmodule.c -o build/temp.macosx-10.15-x86_64-3.7/psycopg/psycopgmodule.o
    In file included from psycopg/psycopgmodule.c:28:
    In file included from ./psycopg/psycopg.h:35:
    In file included from /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include/Python.h:8:
    /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/include/pyconfig.h:59:10: fatal error: 'io.h' file not found
    #include <io.h>
             ^~~~~~
    1 error generated.

    It appears you are missing some prerequisite to build the package from source.

    You may install a binary package by installing 'psycopg2-binary' from PyPI.
    If you want to install psycopg2 from source, please install the packages
    required for the build and try again.

    For further information please check the 'doc/src/install.rst' file (also at
    <https://www.psycopg.org/docs/install.html>).

    error: command 'clang' failed with exit status 1
    ----------------------------------------
ERROR: Command errored out with exit status 1: /Users/nicolasrizzoehrenbock/Documents/ContactBook/venv/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"'; __file__='"'"'/private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-install-mpy9u7el/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /private/var/folders/yj/3jfym00d7r3_f9_jmkrt999r0000gn/T/pip-record-3cminrp4/install-record.txt --single-version-externally-managed --compile --install-headers /Users/Documents/venv/include/site/python3.7/psycopg2 Check the logs for full command output.

I tried doing pip install psycopg2-binary but i have it already installed. I also tried in already asked questions but nothing worked. Thanks in advance

Answer 1

psycopg2-binary is not a dependency of psycopg2 . It is a replacement.

So if psyocpg2 fails to install, just install psycopg2-binary instead.

The difference boils down to compilation. psycopg2-binary is a pre-compiled binary whereas psycopg2 will be compiled specifically for your system. It is preferred but if you do not have an appropriate compiler installed then the installation will fail. In this case you can use the pre-compiled binary psycopg2-binary instead. It is a drop-in replacement (ie you still use import psycopg2 ).