How do I increase the gRPC message size limit in Sandbox?

I’m trying to submit a big transaction. Both Sandbox and Sandbox classic throw the error

Exception in thread "main" io.grpc.StatusRuntimeException: RESOURCE_EXHAUSTED: gRPC message exceeds maximum size 4194304: 27317399

I’ve tried several variations of the --maxInboundMessageSize flag, but none of them seem to have an effect:

daml start --sandbox-option="--maxInboundMessageSize=41943040"
daml start --sandbox-classic --sandbox-option="--maxInboundMessageSize=41943040"
daml start --sandbox-option="--maxInboundMessageSize" --sandbox-option="41943040"
daml start --sandbox-classic --sandbox-option="--maxInboundMessageSize" --sandbox-option="41943040"
daml start --sandbox-option=--maxInboundMessageSize --sandbox-option=41943040
daml start --sandbox-classic --sandbox-option=--maxInboundMessageSize --sandbox-option=41943040

Am I doing something wrong setting this flag? Am I setting the wrong flag? How do I increase the message size limit?

Does it work if you run sandbox outside of daml start?

daml sandbox --maxInboundMessageSize=41943040

RESOURCE_EXAUSTED is supposed to be the backpressure status code in the ledger-api, so you shouldn’t be seeing that specific error for that condition. Worth reporting it as a bug at Issues · digital-asset/daml · GitHub.

@gerolf, same problem with daml sandbox and daml sandbox-classic.
@Andrae you make a good point.

I’ve opened two issues: #5992 #5993

@bernhard: a shot in the dark, did you also increase the maxInboundMessageSize of your client application (assuming it is written for the JVM using Netty).