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Disable virtualenv's download-by-default in tox

Project description

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Disable virtualenv (>=14)'s downloading behaviour when running through tox.

Wait, why?

A few goals for test suites are repeatability and speed. In modern versions of virtualenv (>=14), virtualenv will reach out to pypi to download the latest version of pip, setuptools, and wheel even when it has a perfectly good copy of the wheeled packages on disk.

A few reasons why downloading is problematic:

  • Reaching out to the network is slow.
  • pypi goes down quite often
  • You may work in a situation where installation should not come from public pypi.
  • If you don't have a network connection, virtualenv will outright fail.
  • Hurts repeatability as you may suddenly get a new version of setuptools / pip
  • setuptools has been unstable in the past, breaking their latest version and compatibility.

How it works

The downloading behaviour of virtualenv can be disabled either by calling virtualenv --no-download or by setting the environment variable VIRTUALENV_NO_DOWNLOAD. This tox plugin sets that environment variable during the virtualenv creation.


$ pip install tox-virtualenv-no-download
# just use tox as you usually would
$ tox ...

Project details

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Files for tox-virtualenv-no-download, version 1.1.0
Filename, size File type Python version Upload date Hashes
Filename, size tox_virtualenv_no_download-1.1.0-py2.py3-none-any.whl (3.7 kB) File type Wheel Python version py2.py3 Upload date Hashes View hashes
Filename, size tox_virtualenv_no_download-1.1.0.tar.gz (2.3 kB) File type Source Python version None Upload date Hashes View hashes

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