Installing scikit-learn from the main branch fails with `scikit-learn requires numpy >= 1.14.6`

Describe the bug

pip install git+https://github.com/scikit-learn/scikit-learn.git

fails with the following error:

$ pip install git+https://github.com/scikit-learn/scikit-learn.git
Collecting git+https://github.com/scikit-learn/scikit-learn.git
  Cloning https://github.com/scikit-learn/scikit-learn.git to /tmp/pip-req-build-xbo_4nwf
  Running command git clone -q https://github.com/scikit-learn/scikit-learn.git /tmp/pip-req-build-xbo_4nwf
  Installing build dependencies: started
  Installing build dependencies: still running...
  Installing build dependencies: still running...
  Installing build dependencies: still running...
  Installing build dependencies: still running...
  Installing build dependencies: still running...
  Installing build dependencies: finished with status 'done'
  Getting requirements to build wheel: started
  Getting requirements to build wheel: finished with status 'done'
    Preparing wheel metadata: started
    Preparing wheel metadata: finished with status 'error'
    ERROR: Command errored out with exit status 1:
     command: /usr/share/miniconda/bin/python /usr/share/miniconda/lib/python3.7/site-packages/pip/_vendor/pep517/in_process/_in_process.py prepare_metadata_for_build_wheel /tmp/tmpmzvhqjhs
         cwd: /tmp/pip-req-build-xbo_4nwf
    Complete output (24 lines):
    Partial import of sklearn during the build process.
    Traceback (most recent call last):
      File "/usr/share/miniconda/lib/python3.7/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 280, in <module>
        main()
      File "/usr/share/miniconda/lib/python3.7/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 263, in main
        json_out['return_val'] = hook(**hook_input['kwargs'])
      File "/usr/share/miniconda/lib/python3.7/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 133, in prepare_metadata_for_build_wheel
        return hook(metadata_directory, config_settings)
      File "/tmp/pip-build-env-jjptwtgc/overlay/lib/python3.7/site-packages/setuptools/build_meta.py", line 166, in prepare_metadata_for_build_wheel
        self.run_setup()
      File "/tmp/pip-build-env-jjptwtgc/overlay/lib/python3.7/site-packages/setuptools/build_meta.py", line 259, in run_setup
        self).run_setup(setup_script=setup_script)
      File "/tmp/pip-build-env-jjptwtgc/overlay/lib/python3.7/site-packages/setuptools/build_meta.py", line 150, in run_setup
        exec(compile(code, __file__, 'exec'), locals())
      File "setup.py", line 300, in <module>
        setup_package()
      File "setup.py", line 286, in setup_package
        check_package_status('numpy', min_deps.NUMPY_MIN_VERSION)
      File "setup.py", line 223, in check_package_status
        req_str, instructions))
    ImportError: Your installation of numpy 1.14.5 is out-of-date.
    scikit-learn requires numpy >= 1.14.6.
    Installation instructions are available on the scikit-learn website: http://scikit-learn.org/stable/install.html

Steps/Code to Reproduce

pip install git+https://github.com/scikit-learn/scikit-learn.git

Expected Results

pip install git+https://github.com/scikit-learn/scikit-learn.git

should successfully install the dev version of scikit-learn

Actual Results

Versions

I’m using Python 3.7.

[ogrisel]

I merged #20184, let’s see if it works as expected.

[thomasjpfan]

Merging https://github.com/scikit-learn/scikit-learn/pull/20184 should resolve this issue. (Although it means we are deviating a little from oldest-supported-numpy)