diff --git a/src/test/py/bazel/runfiles_test.py b/src/test/py/bazel/runfiles_test.py
index f5bb9b2ff66adb..633548d2580a2f 100644
--- a/src/test/py/bazel/runfiles_test.py
+++ b/src/test/py/bazel/runfiles_test.py
@@ -47,13 +47,9 @@ def _AssertRunfilesLibraryInBazelToolsRepo(self, family, lang_name):
     self.AssertExitCode(exit_code, 0, stderr)
     bazel_bin = stdout[0]
 
-    # TODO(brandjon): (Issue #8169) Make this test compatible with Python
-    # toolchains. Blocked on the fact that there's no PY3 environment on our Mac
-    # workers (bazelbuild/continuous-integration#578).
     exit_code, _, stderr = self.RunBazel([
         "build",
         "--verbose_failures",
-        "--incompatible_use_python_toolchains=false",
         "//foo:runfiles-" + family
     ])
     self.AssertExitCode(exit_code, 0, stderr)
diff --git a/tools/python/pywrapper_test.py b/tools/python/pywrapper_test.py
index 14fd0d70e41c62..f5eacd54c6ce61 100644
--- a/tools/python/pywrapper_test.py
+++ b/tools/python/pywrapper_test.py
@@ -86,7 +86,12 @@ def setup_tool(self, cmd):
     path = which(cmd)
     self.assertIsNotNone(
         path, msg="Could not locate '%s' command on PATH" % cmd)
-    self.CopyFile(path, os.path.join("dir", cmd), executable=True)
+    # On recent MacOs versions, copying the coreutils tools elsewhere doesn't
+    # work -- they simply fail with "Killed: 9". To workaround that, just
+    # re-exec the actual binary.
+    self.ScratchFile("dir/" + cmd,
+                     ["#!/bin/sh", 'exec {} "$@"'.format(cmd)],
+                     executable=True)
 
   def locate_runfile(self, runfile_path):
     resolved_path = self.Rlocation(runfile_path)