diff --git a/setup.py b/setup.py
index d09be30cf..ff037a496 100755
--- a/setup.py
+++ b/setup.py
@@ -1218,14 +1218,19 @@ def clean(all_):
     ret.append(f'{g_root}/src/build')
     
     path_mupdf, _ = get_mupdf()
-    ret.append(f'{path_mupdf}/platform/c++')
-    ret.append(f'{path_mupdf}/platform/python')
+    
+    # We remove mupdf directories directly with shutil.rmtree() instead of
+    # returning them to pipcl, because pipcl will deliberately fail if asked to
+    # remove things that are outside our checkout.
+    shutil.rmtree(f'{path_mupdf}/platform/c++', ignore_errors=True)
+    shutil.rmtree(f'{path_mupdf}/platform/python', ignore_errors=True)
+    
     if all_:
         # Clean mupdf C library.
-        ret.append(f'{path_mupdf}/build')
-        ret.append(f'{path_mupdf}/platform/win32')
-        ret.append(f'{path_mupdf}/platform/win32/Release')
-        ret.append(f'{path_mupdf}/platform/win32/x64')
+        shutil.rmtree(f'{path_mupdf}/build', ignore_errors=True)
+        shutil.rmtree(f'{path_mupdf}/platform/win32', ignore_errors=True)
+        shutil.rmtree(f'{path_mupdf}/platform/win32/Release', ignore_errors=True)
+        shutil.rmtree(f'{path_mupdf}/platform/win32/x64', ignore_errors=True)
     
     pipcl.log(f'Returning: {ret=}')
     return ret
@@ -1438,9 +1443,10 @@ def platform_release_tuple():
             print(f'OpenBSD: pip install of swig does not build; assuming `pkg_add swig`.')
         elif PYMUPDF_SETUP_SWIG:
             pass
-        elif darwin or os.environ.get('PYODIDE_ROOT'):
+        elif os.environ.get('PYODIDE_ROOT'):
             # 2025-10-27: new swig-4.4.0 fails badly at runtime on macos.
             # 2025-11-06: similar for pyodide.
+            # 2026-02-24: Appears to work on macos with swig 4.4.1.
             ret.append('swig==4.3.1')
         else:
             ret.append('swig')
diff --git a/tests/conftest.py b/tests/conftest.py
index 44c5e4d02..c79e69906 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -38,6 +38,11 @@ def install_required_packages():
 
 install_required_packages()
 
+
+@pytest.fixture(scope="session", autouse=True)
+def log_global_env_facts(record_testsuite_property):
+    record_testsuite_property('platform.python_version()', platform.python_version())
+
 # Need to import pymupdf only after we've installed pymupdf-fonts above,
 # because pymupdf imports pymupdf_fonts, and copes with import failure.
 import pymupdf