diff --git a/tests/hghave.py b/tests/hghave.py
--- a/tests/hghave.py
+++ b/tests/hghave.py
@@ -202,6 +202,22 @@ def has_pyoxidizer():
     return 'PYOXIDIZED_INSTALLED_AS_HG' in os.environ
 
 
+@check(
+    "pyoxidizer-in-memory",
+    "running with pyoxidizer build as 'hg' with embedded resources",
+)
+def has_pyoxidizer():
+    return 'PYOXIDIZED_IN_MEMORY_RSRC' in os.environ
+
+
+@check(
+    "pyoxidizer-in-filesystem",
+    "running with pyoxidizer build as 'hg' with external resources",
+)
+def has_pyoxidizer():
+    return 'PYOXIDIZED_FILESYSTEM_RSRC' in os.environ
+
+
 @check("cvs", "cvs client/server")
 def has_cvs():
     re = br'Concurrent Versions System.*?server'
diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -3451,6 +3451,9 @@ class TestRunner:
                 verbosity = 2
             runner = TextTestRunner(self, verbosity=verbosity)
 
+            osenvironb.pop(b'PYOXIDIZED_IN_MEMORY_RSRC', None)
+            osenvironb.pop(b'PYOXIDIZED_FILESYSTEM_RSRC', None)
+
             if self.options.list_tests:
                 result = runner.listtests(suite)
             else:
@@ -3886,6 +3889,20 @@ class TestRunner:
             sys.stdout.buffer.write(out)
             sys.exit(1)
 
+        cmd = _bytes2sys(b"%s debuginstall -Tjson" % self._hgcommand)
+        p = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True)
+        out, err = p.communicate()
+
+        props = json.loads(out)[0]
+
+        # Affects hghave.py
+        osenvironb.pop(b'PYOXIDIZED_IN_MEMORY_RSRC', None)
+        osenvironb.pop(b'PYOXIDIZED_FILESYSTEM_RSRC', None)
+        if props["hgmodules"] == props["pythonexe"]:
+            osenvironb[b'PYOXIDIZED_IN_MEMORY_RSRC'] = b'1'
+        else:
+            osenvironb[b'PYOXIDIZED_FILESYSTEM_RSRC'] = b'1'
+
     def _outputcoverage(self):
         """Produce code coverage output."""
         import coverage