Merge pull request #564 from opensafely-core/fix-windows-again

fix: more careful tempfile handling

jobrunner/executors/volumes.py

@@ -1,5 +1,6 @@
 import importlib
 import logging
+import os
 import shutil
 import tempfile
 import time
@@ -49,11 +50,17 @@ def delete_volume(job):
         docker.delete_volume(docker_volume_name(job))
 
     def write_timestamp(job, path, timeout=None):
-        with tempfile.NamedTemporaryFile("w") as f:
-            f.write(str(time.time_ns()))
-            f.flush()
+        try:
+            f = tempfile.NamedTemporaryFile(delete=False)
+            f.close()
             p = Path(f.name)
+            p.write_text(str(time.time_ns()))
             docker.copy_to_volume(docker_volume_name(job), p, path, timeout)
+        finally:
+            try:
+                os.remove(f.name)
+            except Exception:
+                pass
 
     def read_timestamp(job, path, timeout=None):
         return docker.read_timestamp(docker_volume_name(job), path, timeout)