Use tox 4.0 in CI

.circleci/config.yml

@@ -22,7 +22,7 @@ jobs:
           command: |
               sudo apt update
               sudo apt install texlive texlive-latex-extra texlive-fonts-recommended dvipng cm-super
-              pip install pip "tox<4"
+              pip install pip tox --upgrade
       - run:
           name: Run tests
           command: tox -v

.github/workflows/ci_cron_daily.yml

@@ -39,7 +39,6 @@ jobs:
       fail-fast: false
       matrix:
         include:
-
           - name: Bundling with pyinstaller
             os: ubuntu-latest
             python: 3.8
@@ -57,16 +56,20 @@ jobs:
       uses: actions/checkout@v3
       with:
         fetch-depth: 0
+
     - name: Set up Python
       uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python }}
+
     - name: Install language-pack-de and tzdata
       if: ${{ matrix.os == 'ubuntu-latest' }}
       run: |
         sudo apt-get update
         sudo apt-get install language-pack-de tzdata
+
     - name: Install Python dependencies
-      run: python -m pip install "tox<4"
+      run: python -m pip install --upgrade tox
+
     - name: Run tests
       run: tox ${{ matrix.toxargs}} -e ${{ matrix.toxenv}} -- ${{ matrix.toxposargs}}

.github/workflows/ci_cron_weekly.yml

@@ -83,7 +83,7 @@ jobs:
       if: ${{ matrix.toxenv == 'linkcheck' }}
       run: sudo apt-get install graphviz
     - name: Install Python dependencies
-      run: python -m pip install --upgrade "tox<4"
+      run: python -m pip install --upgrade tox
     - name: Run tests
       run: tox ${{ matrix.toxargs}} -e ${{ matrix.toxenv}} -- ${{ matrix.toxposargs}}
 

.github/workflows/ci_workflows.yml

@@ -50,7 +50,6 @@ jobs:
     with:
       submodules: false
       coverage: codecov
-      toxdeps: "'tox<4'"
       libraries: |
         apt:
           - language-pack-fr
@@ -87,7 +86,6 @@ jobs:
     with:
       submodules: false
       coverage: codecov
-      toxdeps: "'tox<4'"
       libraries: |
         apt:
           - language-pack-de
@@ -118,7 +116,7 @@ jobs:
     # test the ability to run the test suite in parallel.
     # Numpy is pinned to avoid building it from source for numpy 1.21.5
     - name: Install dependencies for Python 3.8
-      run: /opt/python/cp38-cp38/bin/pip install "tox<4"
+      run: /opt/python/cp38-cp38/bin/pip install --upgrade tox
     - name: Run tests for Python 3.8
       run: /opt/python/cp38-cp38/bin/python -m tox -e py38-numpy120-test -- -n=4 --durations=50
     # We use the 3.8 build to check that running tests twice in a row in the

tox.ini

@@ -11,8 +11,6 @@ requires =
     setuptools >= 30.3.0
     pip >= 19.3.1
     tox-pypi-filter >= 0.12
-    tox < 4
-isolated_build = true
 
 [testenv]
 
@@ -23,7 +21,7 @@ isolated_build = true
 pypi_filter = https://raw.githubusercontent.com/astropy/ci-helpers/main/pip_pinnings.txt
 
 # Pass through the following environment variables which are needed for the CI
-passenv = HOME WINDIR LC_ALL LC_CTYPE CC CI IS_CRON ARCH_ON_CI
+passenv = HOME,WINDIR,LC_ALL,LC_CTYPE,CC,CI,IS_CRON,ARCH_ON_CI
 
 setenv =
     NUMPY_WARN_IF_NO_MEM_POLICY = 1
@@ -34,6 +32,8 @@ setenv =
     clocale: LC_CTYPE = C.ascii
     clocale: LC_ALL = C
     devdeps: PIP_EXTRA_INDEX_URL = https://pypi.anaconda.org/scipy-wheels-nightly/simple
+    PYTHONHASHSEED = 1
+
 
 # Run the tests in a temporary directory to make sure that we don't import
 # astropy from the source tree
@@ -132,7 +132,8 @@ pip_pre =
     predeps: true
     !predeps: false
 
-# This lets developers to use tox to build docs and ignores warnings.
+
+# This lets developers use tox to build docs and ignores warnings.
 # This is not used in CI; For that, we have RTD PR builder.
 [testenv:build_docs]
 changedir = docs