providers: allow parallel installations when not running as a snap

snapcraft/providers.py

@@ -34,6 +34,7 @@
     get_managed_environment_log_path,
     get_managed_environment_project_path,
     get_managed_environment_snap_channel,
+    is_snapcraft_running_from_snap,
 )
 
 SNAPCRAFT_BASE_TO_PROVIDER_BASE = {
@@ -183,12 +184,14 @@ def get_base_configuration(
         )
         snap_name = "snapcraft"
         snap_channel = "stable"
-    else:
-        # Use SNAP_INSTANCE_NAME for snapcraft's snap name, as it may not be 'snapcraft'
-        # if the '--name' parameter was used to install snapcraft.
-        # If snapcraft is not running as a snap, then envvar will not exist so default
-        # to 'snapcraft'.
+    elif is_snapcraft_running_from_snap():
+        # Use SNAP_INSTANCE_NAME for snapcraft's snap name, as it may not be
+        # 'snapcraft' if the '--name' parameter was used to install snapcraft.
         snap_name = os.getenv("SNAP_INSTANCE_NAME", "snapcraft")
+    else:
+        # If snapcraft is not running as a snap, then envvar may not exist so
+        # default to 'snapcraft'.
+        snap_name = "snapcraft"
 
     return bases.BuilddBase(
         alias=alias,

tests/unit/test_providers.py

@@ -183,6 +183,9 @@ def test_get_base_configuration(
 ):
     """Verify the base configuration is properly configured."""
     mocker.patch("sys.platform", "linux")
+    mocker.patch(
+        "snapcraft.providers.is_snapcraft_running_from_snap", return_value=True
+    )
     mocker.patch(
         "snapcraft.providers.get_managed_environment_snap_channel",
         return_value="test-channel",
@@ -268,6 +271,9 @@ def test_get_base_configuration_snap_instance_name_default(
 ):
     """If `SNAP_INSTANCE_NAME` does not exist, use the default name 'snapcraft'."""
     mocker.patch("sys.platform", "linux")
+    mocker.patch(
+        "snapcraft.providers.is_snapcraft_running_from_snap", return_value=True
+    )
     mocker.patch(
         "snapcraft.providers.get_managed_environment_snap_channel",
         return_value=None,
@@ -292,6 +298,40 @@ def test_get_base_configuration_snap_instance_name_default(
     )
 
 
+def test_get_base_configuration_snap_instance_name_not_running_as_snap(
+    tmp_path,
+    mocker,
+    monkeypatch,
+):
+    """If snapcraft is not running as a snap, then use the default name 'snapcraft'."""
+    mocker.patch(
+        "snapcraft.providers.is_snapcraft_running_from_snap", return_value=False
+    )
+    mocker.patch("sys.platform", "linux")
+    mocker.patch(
+        "snapcraft.providers.get_managed_environment_snap_channel",
+        return_value=None,
+    )
+    mocker.patch("snapcraft.providers.get_command_environment")
+    mocker.patch("snapcraft.providers.get_instance_name")
+    mock_buildd_base = mocker.patch("snapcraft.providers.bases.BuilddBase")
+    monkeypatch.setenv("SNAP_INSTANCE_NAME", "other-snap")
+
+    providers.get_base_configuration(
+        alias=bases.BuilddBaseAlias.JAMMY,
+        instance_name="test-instance-name",
+    )
+
+    mock_buildd_base.assert_called_with(
+        alias=ANY,
+        compatibility_tag=ANY,
+        environment=ANY,
+        hostname=ANY,
+        snaps=[bases.buildd.Snap(name="snapcraft", channel=None, classic=True)],
+        packages=ANY,
+    )
+
+
 def test_get_command_environment(mocker, mock_default_command_environment):
     """Verify command environment is properly constructed."""
     command_environment = providers.get_command_environment()