attempts to pacify windows runner (which failed on all the examples d…

…ue to an unescaped C:\Users mis-interpreting the \U as a unicode escape sequence) and get more information out of macos runner failure of test_loft_py (where the assertion was uninformative)

examples/loft.py

@@ -41,7 +41,11 @@
     top_bottom = art.faces().filter_by(GeomType.PLANE)
     offset(openings=top_bottom, amount=0.5)
 
-assert abs(art.part.volume - 1306.3405290344635) < 1e-3
+want = 1306.3405290344635
+got = art.part.volume
+delta = abs(got - want)
+tolerance = 1e-3
+assert delta < tolerance, f'{delta=} is greater than {tolerance=}; {got=}, {want=}'
 
 show(art, names=["art"])
 # [End]

tests/test_examples.py

@@ -57,7 +57,7 @@ def assert_example_does_not_raise(self):
                 [
                     sys.executable,
                     "-c",
-                    f"exec(open('{mock_ocp_vscode}').read()); exec(read_and_absolutify('{path}'))",
+                    f"exec(open(r'{mock_ocp_vscode}').read()); exec(read_and_absolutify('{path}'))",
                 ],
                 capture_output=True,
                 cwd=tmpdir,