Is psycopg supported? (Postgresql)

[BartStolarek]

Hi Beeware team

Firstly got to say all of your work is pretty amazing.

I'm putting together a android app for my own personal use, and one of the third party packages I'm using is psycopg2, and connecting to AWS. The build works fine on my desktop, but web and android I'm getting build errors. I will keep trying to debug myself, but its getting late and am hoping someone will save me a ton of time tomorrow haha.

Error from console (I'll post the log in the next comment):

`
briefcase build android

      [familybudget] Updating app metadata...
      Setting main module... done
                                                                                                                                                                                                                                                                                                                                                                                                                                              
      [familybudget] Building Android APK...
                                                                                                                                                                                                                                                                                                                                                                                                                                              
       Configure project :app
      Warning: Python version 3.10 may have fewer packages available. If you experience problems, try switching to version 3.8.
      
       Task :app:preBuild UP-TO-DATE
       Task :app:preDebugBuild UP-TO-DATE
       Task :app:compileDebugAidl NO-SOURCE
       Task :app:compileDebugRenderscript NO-SOURCE
       Task :app:generateDebugBuildConfig
       Task :app:extractPythonBuildPackages
      
       Task :app:generateDebugPythonRequirements
      Chaquopy: Installing for arm64-v8a
      Looking in indexes: https://pypi.org/simple, https://chaquo.com/pypi-7.0, https://chaquo.com/pypi-13.1
      Collecting httpx
        Using cached httpx-0.24.0-py3-none-any.whl (75 kB)
      Collecting psycopg2
        Using cached psycopg2-2.9.6.tar.gz (383 kB)
          ERROR: Command errored out with exit status 1:
           command: 'C:\Users\Bart\CodeProjects\familybudgetbeeware\beeware-venv\Scripts\python.exe' -S -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\Bart\\AppData\\Local\\Temp\\pip-install-dg259bgl\\psycopg2\\setup.py'"'"'; __file__='"'"'C:\\Users\\Bart\\AppData\\Local\\Temp\\pip-install-dg259bgl\\psycopg2\\setup.py'"'"';import chaquopy_monkey; chaquopy_monkey.disable_native();f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' --no-user-cfg egg_info --egg-base 'C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u'
               cwd: C:\Users\Bart\AppData\Local\Temp\pip-install-dg259bgl\psycopg2\
          Complete output (23 lines):
          running egg_info
          creating C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u\psycopg2.egg-info
          writing C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u\psycopg2.egg-info\PKG-INFO
          writing dependency_links to C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u\psycopg2.egg-info\dependency_links.txt
          writing top-level names to C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u\psycopg2.egg-info\top_level.txt
          writing manifest file 'C:\Users\Bart\AppData\Local\Temp\pip-pip-egg-info-smly018u\psycopg2.egg-info\SOURCES.txt'

          Error: pg_config executable not found.
      
          pg_config is required to build psycopg2 from source.  Please add the directory
          containing pg_config to the $PATH or specify the full executable path with the
          option:
          
              python setup.py build_ext --pg-config /path/to/pg_config build ...
      
          or with the pg_config option in 'setup.cfg'.
      
          If you prefer to avoid building psycopg2 from source, please install the PyPI
          'psycopg2-binary' package instead.
      
          For further information please check the 'doc/src/install.rst' file (also at
          <https://www.psycopg.org/docs/install.html>).

              ----------------------------------------
          ERROR: Failed to install psycopg2 from https://files.pythonhosted.org/packages/af/c4/5726cddb53fe52f0e839eb3da04322364f14493217ebd5818cc5e4c948a5/psycopg2-2.9.6.tar.gz#sha256=f15158418fd826831b28585e2ab48ed8df2d0d98f502a2b4fe619e7d5ca29011 (from -r requirements.txt (line 2)).
          For assistance, please raise an issue at https://github.com/chaquo/chaquopy/issues.
          Chaquopy: Exit status 1
          
           Task :app:generateDebugPythonRequirements FAILED
          
          FAILURE: Build failed with an exception.
          
          * What went wrong:
          Execution failed for task ':app:generateDebugPythonRequirements'.
           Process 'command 'python'' finished with non-zero exit value 1
          
            To view full details in Android Studio:
            * Click the 'Build: failed' caption to the left of this message.
            * Then scroll up to see the full output.
          
          * Try:
          Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
          
          * Get more help at https://help.gradle.org
          
          BUILD FAILED in 7s
          3 actionable tasks: 3 executed
          Building...
                                                                                                                                                                                                                                                                                                                                                                                                                                                  
          Error while building  project.

`

[BartStolarek]

briefcase.2023_05_01-21_27_38.build.log

[rmartin16]

The psycopg2 Python package is a wrapper for libpq, a library written in C. Any Python package that is not pure Python must be specially built for the target platform, i.e. Android and iOS. This is the issue tracking this for Android for BeeWare. It suggests an SO post with methods to connect to postgres that might help in the interim.

[freakboy3742]

Another option - psycopg3 can be installed as a pure python package, as well as supporting other features that are useful on mobile like asynchronous API access.

It still requires libpq, but it might be easier to source a copy of libpq than to compile a binary wheel for Android/iOS.

[BartStolarek]

Thanks @rmartin16 for the context, that helps and am keen to learn how to build a package. I saw this tutorial in the beeware docs Contribute First Time, will work through it

Thank you @freakboy3742, that has helped, although I am struggling to find a copy of libpq that is pure python or similar (if I understand correctly).

I did find this though Python drivers for PostgreSQL, since I'm not married to using psycopg, I've replaced it with pg8000 which is pure python, and this fixed my issue :)

[mhsmith]

Thanks, I'll add that link to the Chaquopy issue.

For future reference, if you need to build a package for Android, the place to start is here.