#4457 block numpy import if not needed

xpra/scripts/main.py

@@ -2116,6 +2116,21 @@ def enforce_client_features() -> None:
         "network_listener": "xpra.client.mixins.network_listener",
         "encoding": "xpra.client.mixins.encodings",
     })
+    may_block_numpy()
+
+
+def may_block_numpy() -> None:
+    if envbool("XPRA_MAY_BLOCK_NUMPY", True) and "numpy" not in sys.modules:
+        reason = ""
+        try:
+            from xpra.codecs.nvidia.util import has_nvidia_hardware
+            if not has_nvidia_hardware():
+                reason = "no nvidia hardware"
+        except ImportError:
+            reason = "no nvidia codecs"
+        if reason:
+            get_logger().debug(f"{reason}, blocking `numpy` import")
+            sys.modules["numpy"] = None
 
 
 def make_client(opts):

xpra/scripts/server.py

@@ -29,6 +29,7 @@
     make_progress_process,
     load_pid,
     X11_SOCKET_DIR,
+    may_block_numpy,
 )
 from xpra.scripts.config import (
     InitException, InitInfo, InitExit,
@@ -359,6 +360,7 @@ def enforce_server_features() -> None:
         "windows": "xpra.server.mixins.window,xpra.server.source.windows",
         "rfb": "xpra.net.rfb,xpra.server.rfb",
     })
+    may_block_numpy()
 
 
 def make_monitor_server():