Update programs using simple error mapping to use CustomError

programs/token/src/lib.rs

@@ -2,7 +2,7 @@ use log::*;
 use solana_sdk::account::KeyedAccount;
 use solana_sdk::native_program::ProgramError;
 use solana_sdk::pubkey::Pubkey;
-use solana_sdk::solana_entrypoint;
+use solana_sdk::{custom_error, solana_entrypoint};
 
 mod token_program;
 
@@ -17,6 +17,6 @@ fn entrypoint(
 
     token_program::TokenProgram::process(program_id, info, input).map_err(|err| {
         error!("error: {:?}", err);
-        ProgramError::GenericError
+        ProgramError::CustomError(custom_error!(err))
     })
 }

programs/token/src/token_program.rs

@@ -5,7 +5,7 @@ use solana_sdk::account::KeyedAccount;
 use solana_sdk::pubkey::Pubkey;
 use std;
 
-#[derive(Debug, PartialEq)]
+#[derive(Serialize, Debug, PartialEq)]
 pub enum Error {
     InvalidArgument,
     InsufficentFunds,