Unable to install dev requirements

[modelmat]

Long story short

For some reason I am unable to install the dev requirements, as the pip install -e . command executed by them fails with this code:

if (here / '.git').exists() and not USE_CYTHON:
    print("Install cython when building from git clone", file=sys.stderr)
    print("Hint:", file=sys.stderr)
    print("  pip install cython", file=sys.stderr)
    sys.exit(1)

Yet, opening the python terminal and typing from Cython.Build import cythonize works just fine, and pip freeze shows Cython==0.29.2. This makes me unable to run any tests. Commenting out these lines results in a fully working pip install & make test.

Expected behaviour

Installs fine.

Actual behaviour

I receive this error.

  Installing build dependencies ... done
  Getting requirements to build wheel ... error
  Complete output from command "/home/modelmat/Documents/GitHub Projects/aiohttp/venv/bin/python3" "/home/modelmat/Documents/GitHub Projects/aiohttp/venv/lib/python3.7/site-packages/pip/_vendor/pep517/_in_process.py" get_requires_for_build_wheel /tmp/tmpqx4ffm0k:
  Install cython when building from git clone
  Hint:
    pip install cython

Steps to reproduce

Follow the exact steps as shown in CONTRIBUTING.md.

Your environment

aiohttp: c145bd8416b1edb11214254e07013f92d91b6537
uname -a: Linux desktop 4.20.0-arch1-1-ARCH #1 SMP PREEMPT Mon Dec 24 03:00:40 UTC 2018 x86_64 GNU/Linux

[aio-libs-bot]

GitMate.io thinks the contributor most likely able to help you is @asvetlov.

Possibly related issues are #1562 (add trafaret_config in requirements), #1059 (error install aiohttp), #1801 (Unable to set response.content_length), #3217 (Unable to build RPM package), and #2771 (pip installs old version).

[kxepal]

@modelmat
Are you're using pip==19 to catch this issue? There is a similar issue with it: #3581

[modelmat]

Yes. Should I close this issue then?

[webknjaz]

Duplicate of #3581