[RPC] Some built-in methods error

[Vexed01]

What Red version are you using?

3.4.14

What were you trying to do?

Use the built-in CORE__LOAD RPC method to load a cog via RPC.

What did you expect to happen?

The cog to load and some form of output through RPC confirming it succeeded (which looking at the code would be a tuple)

What actually happened?

The RPC server tried to serialize a tuple (which was returned from CoreLogic._load) but it can't serialize it.

Bot error:

RPC client error:

How can we reproduce this error?

1. Start red with --rpc
2. Start up an RPC client
3. Call the CORE__LOAD function with any arguments
4. Observe RPC returning Internal Error and the bot logs saying serialization error.

Anything else?

Reproduction code, using the RPC library Red uses:

from aiohttp_json_rpc import JsonRpcClient

client = JsonRpcClient()
await client.connect("localhost", 6133)

try:
    await client.call("CORE__LOAD", ["customcom"])  # raises RpcInternalError
finally:
    await client.disconnect()

CORE__RELOAD is broken in the same way as CORE__LOAD

I would expect CORE_UNLOAD to also be broken but instead it does this: