Restore cwd after do_command error WIP

.github/workflows/main.yml

@@ -1,5 +1,5 @@
 name: CmdStanPy
-    
+
 on:
   push:
     branches:
@@ -14,7 +14,7 @@ on:
         description: 'Version to test'
         required: false
         default: 'latest'
-      
+
 jobs:
   get-cmdstan-version:
     # get the latest cmdstan version to use as part of the cache key
@@ -81,11 +81,15 @@ jobs:
       - name: Show libraries
         run: python -m pip freeze
 
+      - name: Get system info
+        uses: kenchan0130/actions-system-info@v1.0.0
+        id: system-info
+
       - name: CmdStan installation cacheing
         uses: actions/cache@v2
         with:
           path: ~/.cmdstan
-          key: ${{ runner.os }}-cmdstan-${{ needs.get-cmdstan-version.outputs.version }}-${{ hashFiles('**/install_cmdstan.py') }}
+          key: ${{ runner.os }}-${{ steps.system-info.outputs.release }}-cmdstan-${{ needs.get-cmdstan-version.outputs.version }}-${{ hashFiles('**/install_cmdstan.py') }}
 
       - name: Install CmdStan (Linux, macOS)
         if: matrix.os != 'windows-latest'

cmdstanpy/utils.py

@@ -1319,8 +1319,10 @@ def pushd(new_dir: str) -> Iterator[None]:
     """Acts like pushd/popd."""
     previous_dir = os.getcwd()
     os.chdir(new_dir)
-    yield
-    os.chdir(previous_dir)
+    try:
+        yield
+    finally:
+        os.chdir(previous_dir)
 
 
 def report_signal(sig: int) -> None:

test/test_utils.py

@@ -45,6 +45,7 @@
     validate_dir,
     windows_short_path,
     write_stan_json,
+    pushd,
 )
 
 HERE = os.path.dirname(os.path.abspath(__file__))
@@ -807,6 +808,17 @@ def test_exit(self):
                 do_command(args, HERE)
 
 
+class PushdTest(unittest.TestCase):
+
+    def test_restore_cwd(self):
+        "Ensure do_command in a different cwd restores cwd after error."
+        cwd = os.getcwd()
+        with self.assertRaises(RuntimeError):
+            with pushd(os.path.dirname(cwd)):
+                raise RuntimeError('error')
+        self.assertEqual(cwd, os.getcwd())
+
+
 class FlattenTest(unittest.TestCase):
     def test_good(self):
         array_3d = np.empty((200, 4, 4))