problemmatcher: Take temporary directory as argument

Hopefully fixes things on Docker

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
           node-version: '12.x'
         if: "matrix.testenv == 'eslint'"
       - name: Set up problem matchers
-        run: "python3 scripts/dev/ci/problemmatchers.py ${{ matrix.testenv }}"
+        run: "python3 scripts/dev/ci/problemmatchers.py ${{ matrix.testenv }} ${{ runner.temp }}"
       - name: Install dependencies
         run: |
             [[ ${{ matrix.testenv }} == eslint ]] && npm install -g eslint
@@ -62,11 +62,14 @@ jobs:
         DOCKER: "${{ matrix.image }}"
         CI: true
         PYTEST_ADDOPTS: "--color=yes"
+      volumes:
+        # Hardcoded because we can't use ${{ runner.temp }} here apparently.
+        - /home/runner/work/_temp/:/home/runner/work/_temp/
       options: --privileged --tty
     steps:
       - uses: actions/checkout@v2
       - name: Set up problem matchers
-        run: "python3 scripts/dev/ci/problemmatchers.py py38"
+        run: "python3 scripts/dev/ci/problemmatchers.py py38 ${{ runner.temp }}"
       - run: tox -e py38
 
   tests:
@@ -142,7 +145,7 @@ jobs:
         with:
           python-version: "${{ matrix.python }}"
       - name: Set up problem matchers
-        run: "python3 scripts/dev/ci/problemmatchers.py ${{ matrix.testenv }}"
+        run: "python3 scripts/dev/ci/problemmatchers.py ${{ matrix.testenv }} ${{ runner.temp }}"
       - name: Install apt dependencies
         run: sudo apt-get install --no-install-recommends libyaml-dev libegl1-mesa libxkbcommon-x11-0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-xinerama0
         if: "startsWith(matrix.os, 'ubuntu-')"

scripts/dev/ci/problemmatchers.py

@@ -26,7 +26,6 @@ https://github.com/actions/toolkit/blob/master/docs/commands.md#problem-matchers
 """
 
 import sys
-import tempfile
 import pathlib
 import json
 
@@ -182,7 +181,7 @@ def add_matcher(output_dir, testenv, data):
     print("::add-matcher::{}".format(output_file))
 
 
-def main():
+def main(testenv, tempdir):
     testenv = sys.argv[1]
     if testenv.startswith('py3'):
         testenv = 'tests'
@@ -190,10 +189,7 @@ def main():
     if testenv not in MATCHERS:
         return
 
-    # We're not deleting the temporary file because this is only running on CI
-    # anyways, and we're not sure if GitHub has already read the file contents
-    # at the point this script exits.
-    output_dir = pathlib.Path(tempfile.mkdtemp(suffix='-ghmatchers'))
+    output_dir = pathlib.Path(tempdir)
 
     add_matcher(output_dir=output_dir,
                 testenv=testenv,
@@ -201,4 +197,4 @@ def main():
 
 
 if __name__ == '__main__':
-    sys.exit(main())
+    sys.exit(main(*sys.argv[1:]))