tox.ini: Add tests for python2

[mkoeppe]

These tests can be run by adding -python2 to the tox environment,
such as

    tox -e local-homebrew-macos-standard-python2
    tox -e docker-ubuntu-bionic-standard-python2

Additionally, now local environments (introduced in #29104 for homebrew) respect the environment variable EXTRA_CONFIGURE_ARGS that was already available for docker environments.

CC: @jhpalmieri @dimpase @mwageringel

Component: porting

Author: Matthias Koeppe

Branch/Commit: a33b72a

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/29367

[mkoeppe]

Branch: u/mkoeppe/tox_ini__add_tests_for_python2

[mkoeppe]

Last 10 new commits:

14a3dab	tox.ini [local]: Disable testsuites for some packages
2553b5a	tox.ini [local]: Disable linbox testsuite
2f79c76	tox.ini: Move homebrew environment settings to script .homebrew-build-env
77d5c11	build/pkgs/ntl/distros/homebrew.txt: Remove ntl
4ec80e2	Remove use of homebrew packages flint, arb
54c803b	build/pkgs/patch/distros/homebrew.txt: New
2ce6e6c	build/pkgs/boost*/distros/homebrew.txt: New
467160c	.gitignore: Add prefix
dfce7d4	tox.ini [local]: Pass MAKE environment variable, do not default to 'make -j12', change default target to 'build', add doc
a33b72a	tox.ini: Add configuration factor 'python2'; [local] respect EXTRA_CONFIGURE_ARGS

[mkoeppe]

Author: Matthias Koeppe

[mkoeppe]

Dependencies: #29104

[mkoeppe]

Commit: a33b72a

[mkoeppe]

Description changed:

--- 
+++ 
@@ -1 +1,11 @@
+These tests can be run by adding `-python2` to the tox environment, 
+such as
 
+```
+    tox -e local-homebrew-macos-standard-python2
+    tox -e docker-ubuntu-bionic-standard-python2
+```
+
+Additionally, now `local` environments (introduced in #29104 for homebrew) respect the environment variable `EXTRA_CONFIGURE_ARGS` that was already available for `docker` environments.
+
+

[mkoeppe]

comment:3

Branch is on top of #29104.

[mkoeppe]

comment:4

Tests run at https://github.com/mkoeppe/sage/actions/runs/60588138

[mkoeppe]

comment:5

On debian-jessie-standard-python2 (https://github.com/mkoeppe/sage/runs/525632981):

  [pynac-0.7.26]   checking for a version of Python >= '2.1.0'... sys:1: RuntimeWarning: not adding directory '' to sys.path since it's not owned by a trusted user.
  [pynac-0.7.26]   Untrusted users could put files in this directory which might then be imported by your Python code. As a general precaution from similar exploits, you should not execute Python code from this directory
  [pynac-0.7.26]   yes
  [pynac-0.7.26]   checking for the distutils Python package... no
  [pynac-0.7.26]   configure: error: cannot import Python module "distutils".

[mkoeppe]

comment:6

Same on debian-buster-standard-python2

[mkoeppe]

comment:7

And on debian-bullseye-standard-python2 both pynac and pip fail

[mkoeppe]

comment:8

The pynac error is caused by the warning sys:1: RuntimeWarning: not adding directory '' to sys.path since it's not owned by a trusted user.,
which is considered an error by pynac's configure.

[mkoeppe]

comment:9

This might be output because we run as root?

[mkoeppe]

comment:10

caused by build/pkgs/python2/patches/sys_path_security-issue_16202.patch, of course.

[mkoeppe]

comment:11

Not a good idea that we output that warning even in noninteractive invocations of PYTHON (python -c)