Collecting pygobject
  Downloading PyGObject-3.38.0.tar.gz (712 kB)
     |████████████████████████████████| 712 kB 14.4 MB/s
  Installing build dependencies ... error
  ERROR: Command errored out with exit status 1:
   command: /app/.heroku/python/bin/python /app/.heroku/python/lib/python3.7/site-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-1v1sz1kl/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo
       cwd: None
  Complete output (52 lines):
  Collecting setuptools
    Downloading setuptools-50.3.0-py3-none-any.whl (785 kB)
  Collecting wheel
    Downloading wheel-0.35.1-py2.py3-none-any.whl (33 kB)
  Collecting pycairo
    Downloading pycairo-1.19.1.tar.gz (205 kB)
  Building wheels for collected packages: pycairo
    Building wheel for pycairo (setup.py): started
    Building wheel for pycairo (setup.py): finished with status 'error'
    ERROR: Command errored out with exit status 1:
     command: /app/.heroku/python/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-cr1ph5wh/pycairo/setup.py'"'"'; __file__='"'"'/tmp/pip-install-cr1ph5wh/pycairo/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 /tmp/pip-wheel-pjlkvor7
         cwd: /tmp/pip-install-cr1ph5wh/pycairo/
    Complete output (12 lines):
    running bdist_wheel
    running build
    running build_py
    creating build
    creating build/lib.linux-x86_64-3.7
    creating build/lib.linux-x86_64-3.7/cairo
    copying cairo/__init__.py -> build/lib.linux-x86_64-3.7/cairo
    copying cairo/__init__.pyi -> build/lib.linux-x86_64-3.7/cairo
    copying cairo/py.typed -> build/lib.linux-x86_64-3.7/cairo
    running build_ext
    'pkg-config' not found.
    Command ['pkg-config', '--print-errors', '--exists', 'cairo >= 1.13.1']
    ----------------------------------------
    ERROR: Failed building wheel for pycairo
    Running setup.py clean for pycairo
  Failed to build pycairo
  Installing collected packages: setuptools, wheel, pycairo
      Running setup.py install for pycairo: started
      Running setup.py install for pycairo: finished with status 'error'
      ERROR: Command errored out with exit status 1:
       command: /app/.heroku/python/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-cr1ph5wh/pycairo/setup.py'"'"'; __file__='"'"'/tmp/pip-install-cr1ph5wh/pycairo/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-4xq73u3w/install-record.txt --single-version-externally-managed --prefix /tmp/pip-build-env-1v1sz1kl/overlay --compile --install-headers /tmp/pip-build-env-1v1sz1kl/overlay/include/python3.7m/pycairo
           cwd: /tmp/pip-install-cr1ph5wh/pycairo/
      Complete output (12 lines):
      running install
      running build
      running build_py
      creating build
      creating build/lib.linux-x86_64-3.7
      creating build/lib.linux-x86_64-3.7/cairo
      copying cairo/__init__.py -> build/lib.linux-x86_64-3.7/cairo
      copying cairo/__init__.pyi -> build/lib.linux-x86_64-3.7/cairo
      copying cairo/py.typed -> build/lib.linux-x86_64-3.7/cairo
      running build_ext
      'pkg-config' not found.
      Command ['pkg-config', '--print-errors', '--exists', 'cairo >= 1.13.1']
      ----------------------------------------
  ERROR: Command errored out with exit status 1: /app/.heroku/python/bin/python -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-cr1ph5wh/pycairo/setup.py'"'"'; __file__='"'"'/tmp/pip-install-cr1ph5wh/pycairo/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-4xq73u3w/install-record.txt --single-version-externally-managed --prefix /tmp/pip-build-env-1v1sz1kl/overlay --compile --install-headers /tmp/pip-build-env-1v1sz1kl/overlay/include/python3.7m/pycairo Check the logs for full command output.
  WARNING: You are using pip version 20.1.1; however, version 20.2.3 is available.
  You should consider upgrading via the '/app/.heroku/python/bin/python -m pip install --upgrade pip' command.
  ----------------------------------------
ERROR: Command errored out with exit status 1: /app/.heroku/python/bin/python /app/.heroku/python/lib/python3.7/site-packages/pip install --ignore-installed --no-user --prefix /tmp/pip-build-env-1v1sz1kl/overlay --no-warn-script-location --no-binary :none: --only-binary :none: -i https://pypi.org/simple -- setuptools wheel pycairo Check the logs for full command output.
WARNING: You are using pip version 20.1.1; however, version 20.2.3 is available.
You should consider upgrading via the '/app/.heroku/python/bin/python -m pip install --upgrade pip' command.