[TIP] Export tox commands for non-toxable environments?

holger krekel holger at merlinux.eu
Thu Nov 29 10:34:26 PST 2012

On Thu, Nov 29, 2012 at 10:02 -0500, Ned Batchelder wrote:
> I'm using tox to run tests on multiple Pythons for coverage.py.  But
> tox won't run on 2.3 or 2.4 (I know, ancient), which coverage.py
> still supports.  I'd like to be able to export the commands tox
> would run so that I can execute them manually in another
> environment.  Something like "tox --dry-run" would be perfect.  It
> would output "pip install REQ" for each requirement, and "CMD" for
> each command.  Does anything like this exist?  Am I missing some
> subtlety that makes this a silly request?
> I can probably hack something together by parsing the tox.ini or the
> output of "tox --showconfig", but that seems like the wrong way to
> make it happen.

"tox -v" will show the commands.  I think they can be automatically
recognized because unlike other lines, they start with two spaces.

You could also use the "--notest" option to skip all testing commands
but that probably doesn't help you much.

As to a "--dry-run" command, it might be a bit tricky because after virtualenv
creation tox searches PATH, including the virtualenv one, for finding
commands and those would need to be special-cased somehow.

FYI there is also someone interested in/working getting back 2.4 support
by including an older virtualenv version with tox, see


> --Ned.
> PS: Is "non-toxic" a better adjective to describe environments tox
> doesn't support? :)

i guess i should have called it "untox" or so :)  OTOH i created the
extra package "detox" for running all things in parallel.  Apart from
not seeing detailed testing progress i don't know a reason not to use it :)

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