diff --git a/pipcl.py b/pipcl.py
index d9b831f70..c25c5118a 100644
--- a/pipcl.py
+++ b/pipcl.py
@@ -2416,6 +2416,8 @@ def openbsd():
 def show_system():
     '''
     Show useful information about the system plus argv and environ.
+    
+    Omits os.environ if $PIPCL_SHOW_ENV is '0'.
     '''
     def log(text):
         log0(text, caller=3)
@@ -2447,10 +2449,18 @@ def log(text):
     for i, arg in enumerate(sys.argv):
         log(f'    {i}: {arg!r}')
     
-    log(f'os.environ ({len(os.environ)}):')
-    for k in sorted( os.environ.keys()):
-        v = os.environ[ k]
-        log( f'    {k}: {v!r}')
+    PIPCL_SHOW_ENV = os.environ.get('PIPCL_SHOW_ENV')
+    if PIPCL_SHOW_ENV == '0':
+        log(f'[Not showing os.environ because {PIPCL_SHOW_ENV=}.]')
+    else:
+        log(f'os.environ ({len(os.environ)}):')
+        for k in sorted( os.environ.keys()):
+            v = os.environ[ k]
+            if 'BEGIN OPENSSH PRIVATE KEY' in v:
+                # Don't show private keys.
+                log(f'    {k} ****')
+            else:
+                log( f'    {k}: {v!r}')
 
 
 class PythonFlags:
diff --git a/scripts/sysinstall.py b/scripts/sysinstall.py
index d4f2fc14f..ea6597d6d 100755
--- a/scripts/sysinstall.py
+++ b/scripts/sysinstall.py
@@ -401,6 +401,7 @@ def run(command, env_extra=None):
                 'test_textbox3',
                 'test_3493',
                 'test_4180',
+                'test_4767',
                 )
         excluded_tests = ' and not '.join(excluded_tests)
         if not pytest_args:
diff --git a/setup.py b/setup.py
index f5d6abad0..709e69489 100755
--- a/setup.py
+++ b/setup.py
@@ -39,6 +39,9 @@
             Directory containing MuPDF libraries, (libmupdf.so,
             libmupdfcpp.so).
     
+    PIPCL_SHOW_ENV
+        If '0', we do not show environment variables on startup.
+    
     PYMUPDF_SETUP_DEVENV
         Location of devenv.com on Windows. If unset we search for it - see
         wdev.py. if that fails we use just 'devenv.com'.
diff --git a/tests/test_4767.py b/tests/test_4767.py
index d3fc318dc..397435edb 100644
--- a/tests/test_4767.py
+++ b/tests/test_4767.py
@@ -9,6 +9,10 @@ def test_4767():
     '''
     Check handling of unsafe paths in `pymupdf embed-extract`.
     '''
+    if os.environ.get('PYODIDE_ROOT'):
+        print('test_4767(): not running on Pyodide - cannot run child processes.')
+        return
+        
     with pymupdf.open() as document:
         document.new_page() 
         document.embfile_add(