Add troubleshoot test

test/test_troubleshooting.py

@@ -0,0 +1,28 @@
+import subprocess
+import pytest
+from .test_projects import TestProject
+from . import utils
+
+so_file_project = TestProject()
+
+so_file_project.files['libnothing.so'] = ''
+
+so_file_project.files['setup.py'] = '''
+raise Exception('this build will fail')
+'''
+
+
+def test_failed_project_with_so_files(tmp_path, capfd):
+    if utils.platform != 'linux':
+        pytest.skip('this test is only relevant to the linux build')
+
+    project_dir = tmp_path / 'project'
+    so_file_project.generate(project_dir)
+
+    with pytest.raises(subprocess.CalledProcessError):
+        utils.cibuildwheel_run(project_dir)
+
+    captured = capfd.readouterr()
+    print('out', captured.out)
+    print('err', captured.err)
+    assert "NOTE: Shared object (.so) files found in this project." in captured.err