Use python3 for every tox env

[dahlia]

As python refers to python2 on many systems (see also PEP 394), coverage-erase could be executed by Python 2 so that it fails.

[etianen]

I'm not sure how this could cause an error. All the python interpreters used by tox will have coverage installed, so all should be able to run coverage erase.

[dahlia]

I'm not sure how this could cause an error. All the python interpreters used by tox will have coverage installed, so all should be able to run coverage erase.

As far as I understand, tox creates a new env which is coverage-erase's own.

The following error is what I experienced:

$ tox -e coverage-erase
coverage-erase create: /.../aiohttp-wsgi/.tox/coverage-erase
coverage-erase installdeps: coverage>=4.1
coverage-erase develop-inst: /.../aiohttp-wsgi
ERROR: invocation failed (exit code 1), logfile: /.../aiohttp-wsgi/.tox/coverage-erase/log/coverage-erase-2.log
ERROR: actionid: coverage-erase
msg: developpkg
cmdargs: ['/.../aiohttp-wsgi/.tox/coverage-erase/bin/pip', 'install', '-e', '/.../aiohttp-wsgi']
env: {'PROJECT_HOME': '/.../, 'VERSIONER_PYTHON_PREFER_32_BIT': 'no', 'LC_CTYPE': 'en_US.UTF-8', 'TMPDIR': '/var/folders/cy/qfns2sx122g0vl7xm_9rf0gw0000gn/T/', 'LOGNAME': 'dahlia', 'USER': 'dahlia', 'PATH': '/.../aiohttp-wsgi/.tox/coverage-erase/bin:/.../.local/bin:/.../Library/Python/2.7/bin:/usr/local/opt/coreutils/libexec/gnubin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin', 'HOME': '/.../, 'TERM': 'xterm-256color', 'SHELL': '/usr/local/bin/bash', 'VERSIONER_PYTHON_VERSION': '2.7', 'VIRTUAL_ENV': '/.../aiohttp-wsgi/.tox/coverage-erase', '_': '/.../.local/bin/tox', 'PWD': '/.../aiohttp-wsgi'}

Obtaining file:///.../aiohttp-wsgi
Collecting aiohttp<2,>=1.2 (from aiohttp-wsgi==0.6.6)
  Using cached aiohttp-1.3.5.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/cy/qfns2sx122g0vl7xm_9rf0gw0000gn/T/pip-build-GCDbXW/aiohttp/setup.py", line 61, in <module>
        raise RuntimeError("aiohttp requires Python 3.4.2+")
    RuntimeError: aiohttp requires Python 3.4.2+

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/cy/qfns2sx122g0vl7xm_9rf0gw0000gn/T/pip-build-GCDbXW/aiohttp/

coverage-erase installed: appdirs==1.4.3,coverage==4.3.4,packaging==16.8,pyparsing==2.2.0,six==1.10.0
___________________________________________________________________ summary ___________________________________________________________________
ERROR:   coverage-erase: InvocationError: /.../aiohttp-wsgi/.tox/coverage-erase/bin/pip install -e /.../aiohttp-wsgi (see /.../aiohttp-wsgi/.tox/coverage-erase/log/coverage-erase-2.log)

[etianen]

Makes sense. Thanks for clarifying!