fall back on stock json if orjson unavailable

pylib/anki/rsbackend.py

@@ -20,7 +20,6 @@ from typing import (
 )
 
 import ankirspy  # pytype: disable=import-error
-import orjson
 
 import anki.backend_pb2 as pb
 import anki.buildinfo
@@ -36,6 +35,19 @@ assert ankirspy.buildhash() == anki.buildinfo.buildhash
 
 SchedTimingToday = pb.SchedTimingTodayOut
 
+try:
+    import orjson
+except:
+    # add compat layer for 32 bit builds that can't use orjson
+    print("reverting to stock json")
+    import json
+
+    class orjson:  # type: ignore
+        def dumps(obj: Any) -> bytes:
+            return json.dumps(obj).encode("utf8")
+
+        loads = json.loads
+
 
 class Interrupted(Exception):
     pass

pylib/setup.py

@@ -21,7 +21,7 @@ setuptools.setup(
         "requests",
         "decorator",
         "protobuf",
-        "orjson",
+        'orjson; platform_machine == "x86_64"',
         'psutil; sys_platform == "win32"',
         'distro; sys_platform != "darwin" and sys_platform != "win32"',
     ],