add problemMatcher

Author: basnijholt

.github/workflows/matchers/pytest.json

@@ -0,0 +1,18 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "python",
+      "pattern": [
+        {
+          "regexp": "^\\s*File\\s\\\"(.*)\\\",\\sline\\s(\\d+),\\sin\\s(.*)$",
+          "file": 1,
+          "line": 2
+        },
+        {
+          "regexp": "^\\s*raise\\s(.*)\\(\\'(.*)\\'\\)$",
+          "message": 2
+        }
+      ]
+    }
+  ]
+}

.github/workflows/tox.yml

@@ -20,10 +20,13 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
+    - name: Register Python problem matcher
+      run: |
+        echo "::add-matcher::.github/workflows/matchers/pytest.json"
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install tox tox-gh-actions
+        pip install tox tox-gh-actions pytest-github-actions-annotate-failures
     - name: Test with tox
       run: tox -vv
       env: