Drop support for tox < 3.13 (< 3.15 with Python 3.8+)

We have tox 3.13 in Fedora 31 running on Python 3.7
We have tox 3.15 in Fedora 32 running on Python 3.8

.github/workflows/main.yaml

@@ -19,10 +19,10 @@ jobs:
         tox_env:
         # This information is repeated in tox.ini
         # (see https://github.com/fedora-python/tox-github-action/issues/8)
-        - py36-tox35
+        - py36-tox313
-        - py37-tox35
+        - py37-tox313
-        - py38-tox35
+        - py38-tox315
-        - py39-tox35
+        - py39-tox315
 
         - py36-toxrelease
         - py37-toxrelease

setup.py

@@ -18,7 +18,13 @@ setup(
     package_dir={"": "src"},
     packages=find_packages("src"),
     entry_points={"tox": ["current-env = tox_current_env.hooks"]},
-    install_requires=["tox>=3.5"],
+    install_requires=[
+        # We support tox 3.13 only to support Fedora 31.
+        # Fedora's tox 3.13 is patched to support Python 3.8 and 3.9,
+        # but the one downloaded from PyPI isn't and it doesn't work properly.
+        "tox>=3.15; python_version >= '3.8'",
+        "tox>=3.13; python_version < '3.8'",
+    ],
     python_requires=">=3.6",
     classifiers=[
         "Development Status :: 3 - Alpha",

src/tox_current_env/hooks.py

@@ -177,10 +177,8 @@ def tox_runtest(venv, redirect):
         return True
 
 
-if hasattr(tox.hookspecs, "tox_cleanup"):
+@tox.hookimpl
-
+def tox_cleanup(session):
-    @tox.hookimpl
-    def tox_cleanup(session):
     """Remove the fake virtualenv not to collide with regular tox
     Collisions can happen anyway (when tox is killed forcefully before this happens)
     Note that we don't remove real venvs, as recreating them is expensive"""

tests/test_integration.py

@@ -49,8 +49,8 @@ def is_available(python):
 
 
 TOX_VERSION = version.parse(tox("--version").stdout.split(" ")[0])
-TOX38 = TOX_VERSION >= version.parse("3.8")
+TOX313 = TOX_VERSION < version.parse("3.14")
-needs_tox38 = pytest.mark.skipif(not TOX38, reason="This test needs at least tox 3.8")
+
 
 needs_py36789 = pytest.mark.skipif(
     not all((is_available(f"python3.{x}") for x in range(6, 10))),
@@ -195,8 +195,10 @@ def test_regular_run():
     assert "/.tox/py39 is the exec_prefix" in lines[3]
     assert "congratulations" in result.stdout
     for y in 6, 7, 8, 9:
-        if y == 9 and not TOX38:
+        if TOX313 and y > 8:
-            # tox 3.5 cannot handle Python 3.9 venvs
+            # there is a bug in tox < 3.14,
+            # it creates venv with /usr/bin/python3 if the version is unknown
+            # See https://src.fedoraproject.org/rpms/python-tox/pull-request/15
             continue
         for pkg in "py", "six", "test":
             sitelib = DOT_TOX / f"py3{y}/lib/python3.{y}/site-packages"
@@ -217,7 +219,6 @@ def test_regular_run_native_toxenv():
         assert len(list(sitelib.glob(f"{pkg}-*.dist-info"))) == 1
 
 
-@needs_tox38
 def test_regular_after_current_is_supported():
     result = tox("-e", NATIVE_TOXENV, "--current-env")
     assert result.stdout.splitlines()[0] == NATIVE_EXEC_PREFIX_MSG
@@ -237,7 +238,6 @@ def test_regular_after_killed_current_is_not_supported():
     assert "--recreate" in result.stderr
 
 
-@needs_tox38
 def test_regular_after_first_deps_only_is_supported():
     result = tox("-e", NATIVE_TOXENV, "--print-deps-only")
     assert result.stdout.splitlines()[0] == "six"

tox.ini

@@ -2,14 +2,15 @@
 
 # This information is repeated in .github/workflows/main.yaml
 # (see https://github.com/fedora-python/tox-github-action/issues/8)
-envlist = {py36,py37,py38,py39}-tox{35,release,master}
+envlist = {py36,py37,py38,py39}-tox{release,master},{py36,py37}-tox313,{py38,py39}-tox315
 
 [testenv]
 deps=
     pytest
     pytest-xdist
     packaging
-    tox35: tox >=3.5,<3.6
+    tox313: tox >=3.13,<3.14
+    tox315: tox >=3.15,<3.16
     toxrelease: tox
     toxmaster: git+https://github.com/tox-dev/tox.git@master
 commands =