Fix SetuptoolsDeprecationWarning about using --global-option

Author: adamchainz

docs/changelog/2478.bugfix.rst

@@ -0,0 +1 @@
+Fixed ``SetuptoolsDeprecationWarning`` about using ``--global-option`` -- by :user:`adamchainz`

src/tox/helper/build_isolated.py

@@ -38,5 +38,5 @@ def _ensure_module_in_paths(module, paths):
 if backend_obj:
     backend = getattr(backend, backend_obj)
 
-basename = backend.build_sdist(dist_folder, {"--global-option": ["--formats=gztar"]})
+basename = backend.build_sdist(dist_folder, {"--build-option": ["--formats=gztar"]})
 print(basename)

tests/unit/package/builder/test_package_builder_isolated.py

@@ -25,6 +25,7 @@ def test_verbose_isolated_build(initproj, mock_venv, cmd):
         },
     )
     result = cmd("--sdistonly", "-v", "-v", "-v", "-e", "py")
+    assert "The arguments ['--formats=gztar'] were given via `--global-option`." not in result.err
     assert "running sdist" in result.out, result.out
     assert "running egg_info" in result.out, result.out
     assert "example123-0.5.tar.gz" in result.out, result.out