Could not build extension anymore

[woprandi]

$ dart run tool/build_extension.dart --prod
Unhandled exception:
Invalid argument(s): Could not find an option named "mv2".
#0      ArgResults.[] (package:args/src/arg_results.dart:69:7)
#1      main (file:///home/william/Documents/Repos/webdev/dwds/debug_extension/tool/build_extension.dart:30:22)
#2      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:295:33)
#3      _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

I guess mv2 option no longer exists