Minting throws no error for duplicate creators

Transaction simulation failed: Error processing Instruction 2: custom program error: 0x3c
Program 11111111111111111111111111111111 invoke [1]
Program 11111111111111111111111111111111 success
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA invoke [1]
Program log: Instruction: InitializeMint
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA consumed 2457 of 200000 compute units
Program TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA success
Program metaqbxxUerdq28cj1RbAWkYQm3ybzjb6a8bt518x1s invoke [1]
Program log: (Deprecated as of 1.1.0) Instruction: Create Metadata Accounts
Program log: Transfer 5616720 lamports to the new account
Program 11111111111111111111111111111111 invoke [2]
Program 11111111111111111111111111111111 success
Program log: Allocate space for the account
Program 11111111111111111111111111111111 invoke [2]
Program 11111111111111111111111111111111 success
Program log: Assign the account to the owning program
Program 11111111111111111111111111111111 invoke [2]
Program 11111111111111111111111111111111 success
Program log: No duplicate creator addresses
Program metaqbxxUerdq28cj1RbAWkYQm3ybzjb6a8bt518x1s consumed 20121 of 200000 compute units
Program metaqbxxUerdq28cj1RbAWkYQm3ybzjb6a8bt518x1s failed: custom program error: 0x3c

No source file, test, or entry point is named. Start by reproducing the mint transaction and tracing the minting path that handles creator addresses, then compare the observed duplicate-creator behavior with the error shown in the transaction log. Done means the intended duplicate-creator error behavior is established and covered by a test.

Written by the indexing model from the issue text.