--live does not symlink on Linux

[lordmauve]

Description

There is an accidental difference between the venvs created when running with --live and --py; when using --live the binaries are copied even on platforms where the default is symlinking. Thus these environments are heavier and slower to create. (Also this triggers a behaviour change with some home-built interpreters so was a cause of test failures.)

This is because python -m venv includes logic to default --symlinks vs --copies whereas [venv.create() simply defaults symlinks=False](https://github.com/python/cpython/blob/8cc5aa47ee464ddfd8da5461edecf4a5c72df2ff/Lib/venv/__init__.py#L562); thxuses the former generally and the latter only for--live`.

To have equivalent behaviour on both paths we need to pass

venv.create(..., symlinks=(os.name != "nt"))

Details

• OS: Linux
• Python version: 3.6+
• thx version: main
• Can you repro on main? Yes
• Can you repro in a clean virtualenv? Yes