argument error

➜  src git:(master) ✗ ./bitcoind -regtest


************************
EXCEPTION: St13runtime_error
Invalid combination of -regtest, -signet, -testnet and -chain. Can use at most one.
bitcoin in AppInit()

Assertion failed: (globalChainBaseParams), function BaseParams, file chainparamsbase.cpp, line 35.
[1]    99784 abort      ./bitcoind -regtest
➜  src git:(master) ✗ ./bitcoind -chain=regtest
Bitcoin Core starting
➜  src git:(master) ✗ ./bitcoin