TST: fix test when not executed from git checkout

Fixes #397.

Author: dnicolodi

tests/test_project.py

@@ -19,7 +19,7 @@
 
 import mesonpy
 
-from .conftest import chdir, package_dir
+from .conftest import chdir, in_git_repo_context, package_dir
 
 
 @pytest.mark.parametrize(
@@ -92,8 +92,9 @@ def wrapper(self, cmd):
         'install-args': ('cli-install',),
     }
 
-    mesonpy.build_sdist(tmp_path, config_settings)
-    mesonpy.build_wheel(tmp_path, config_settings)
+    with in_git_repo_context():
+        mesonpy.build_sdist(tmp_path, config_settings)
+        mesonpy.build_wheel(tmp_path, config_settings)
 
     # check that the right commands are executed, namely that 'meson
     # compile' is used on Windows rather than a 'ninja' direct