[20.x]: regression: no longer works with -p python3.7m

[asottile]

Issue

originally reported here: pre-commit/pre-commit#810 (comment)

this previously worked in the 16.x era

Environment

Provide at least:

• OS: ubuntu 18.04

• pip list of the host python where virtualenv is installed:

   $ pip freeze --all
   appdirs==1.4.3
   distlib==0.3.0
   filelock==3.0.12
   importlib-metadata==1.5.0
   importlib-resources==1.4.0
   pip==20.0.2
   setuptools==46.0.0
   six==1.14.0
   virtualenv==20.0.13
   wheel==0.34.2
   zipp==3.1.0

Output of the virtual environment creation

Make sure to run the creation with -vvv --with-traceback:

$ virtualenv vvv -vvv --with-traceback -p python3.7m
86 setup logging to NOTSET [DEBUG report:43]
129 find interpreter for spec PythonSpec(path=python3.7m) [INFO builtin:44]
130 discover PATH[0]=/home/asottile/bin [DEBUG builtin:84]
130 discover PATH[1]=/home/asottile/bin [DEBUG builtin:84]
130 discover PATH[2]=/usr/local/sbin [DEBUG builtin:84]
130 discover PATH[3]=/usr/local/bin [DEBUG builtin:84]
131 discover PATH[4]=/usr/sbin [DEBUG builtin:84]
131 discover PATH[5]=/usr/bin [DEBUG builtin:84]
131 Attempting to acquire lock 140599339566024 on /home/asottile/.local/share/virtualenv/py_info/20.0.13/7de8334bc336d5cad061541f9e57f300ac341259d2150b7467db7f17faa68e7d.lock [DEBUG filelock:270]
132 Lock 140599339566024 acquired on /home/asottile/.local/share/virtualenv/py_info/20.0.13/7de8334bc336d5cad061541f9e57f300ac341259d2150b7467db7f17faa68e7d.lock [INFO filelock:274]
132 get PythonInfo from /home/asottile/.local/share/virtualenv/py_info/20.0.13/7de8334bc336d5cad061541f9e57f300ac341259d2150b7467db7f17faa68e7d.json for /usr/bin/python3.7m [DEBUG cached_py_info:79]
133 Attempting to release lock 140599339566024 on /home/asottile/.local/share/virtualenv/py_info/20.0.13/7de8334bc336d5cad061541f9e57f300ac341259d2150b7467db7f17faa68e7d.lock [DEBUG filelock:315]
133 Lock 140599339566024 released on /home/asottile/.local/share/virtualenv/py_info/20.0.13/7de8334bc336d5cad061541f9e57f300ac341259d2150b7467db7f17faa68e7d.lock [INFO filelock:318]
133 proposed PathPythonInfo(spec=CPython3.7.7.final.0-64, exe=/usr/bin/python3.7m, platform=linux, version='3.7.7 (default, Mar 10 2020, 15:16:38) \n[GCC 7.5.0]', encoding_fs_io=utf-8-UTF-8) [INFO builtin:50]
134 Attempting to acquire lock 140599339565632 on /home/asottile/.local/share/virtualenv/py_info/20.0.13/767d51c1340bd893661ea55ea3124f6de3c7a262a8b4abca0554b478b1e2ff90.lock [DEBUG filelock:270]
134 Lock 140599339565632 acquired on /home/asottile/.local/share/virtualenv/py_info/20.0.13/767d51c1340bd893661ea55ea3124f6de3c7a262a8b4abca0554b478b1e2ff90.lock [INFO filelock:274]
135 get PythonInfo from /home/asottile/.local/share/virtualenv/py_info/20.0.13/767d51c1340bd893661ea55ea3124f6de3c7a262a8b4abca0554b478b1e2ff90.json for /usr/bin/python [DEBUG cached_py_info:79]
135 Attempting to release lock 140599339565632 on /home/asottile/.local/share/virtualenv/py_info/20.0.13/767d51c1340bd893661ea55ea3124f6de3c7a262a8b4abca0554b478b1e2ff90.lock [DEBUG filelock:315]
135 Lock 140599339565632 released on /home/asottile/.local/share/virtualenv/py_info/20.0.13/767d51c1340bd893661ea55ea3124f6de3c7a262a8b4abca0554b478b1e2ff90.lock [INFO filelock:318]
135 proposed PathPythonInfo(spec=CPython2.7.17.final.0-64, exe=/usr/bin/python, platform=linux2, version='2.7.17 (default, Nov  7 2019, 10:07:09) \n[GCC 7.4.0]', encoding_fs_io=UTF-8-None) [INFO builtin:50]
135 discover PATH[6]=/sbin [DEBUG builtin:84]
136 discover PATH[7]=/bin [DEBUG builtin:84]
136 discover PATH[8]=/usr/games [DEBUG builtin:84]
136 discover PATH[9]=/usr/local/games [DEBUG builtin:84]
Traceback (most recent call last):
  File "/home/asottile/bin/virtualenv", line 8, in <module>
    sys.exit(run_with_catch())
  File "/home/asottile/opt/venv/lib/python3.6/site-packages/virtualenv/__main__.py", line 51, in run_with_catch
    run(args, options)
  File "/home/asottile/opt/venv/lib/python3.6/site-packages/virtualenv/__main__.py", line 20, in run
    session = cli_run(args, options)
  File "/home/asottile/opt/venv/lib/python3.6/site-packages/virtualenv/run/__init__.py", line 27, in cli_run
    session = session_via_cli(args, options)
  File "/home/asottile/opt/venv/lib/python3.6/site-packages/virtualenv/run/__init__.py", line 35, in session_via_cli
    parser = build_parser(args, options)
  File "/home/asottile/opt/venv/lib/python3.6/site-packages/virtualenv/run/__init__.py", line 73, in build_parser
    raise RuntimeError("failed to find interpreter for {}".format(discover))
RuntimeError: failed to find interpreter for Builtin discover of python_spec='python3.7m'

[gaborbernat]

Seems there's not an executable called pyhton3.7m 🤔 on the path; wonder what virtualenv 16 parsed this?

[asottile]

$ which python3.7m
/usr/bin/python3.7m
$ python3.7m --version --version
Python 3.7.7 (default, Mar 10 2020, 15:16:38) 
[GCC 7.5.0]

it's there, just seems virtualenv isn't finding it

[gaborbernat]

Yeah fix already inside #1748 just need to fix Windows tests 👍

[gaborbernat]

released via https://virtualenv.pypa.io/en/latest/changelog.html#v20-0-14-2020-03-25