How to pass vyper compiler args through the CLI

You don’t!

This is a bit of an anti-pattern that moccasin currently does not support. It is much safe to list your compiler args directly in the Vyper files themselves.

Setting the Enable Decimals Flag

In moccasin, you can only set compiler flags like enable-decimals directly in your Vyper smart contract using a source code pragma, as compiler arguments are not supported.

Adding the following pragma to a contract enables decimal support:

# pragma enable-decimals

The enable-decimals flag must be set on the Vyper smart contract itself using this pragma syntax.

Setting the Target EVM Version

When you compile your contract code, you can specify the target Ethereum Virtual Machine version to compile for, to access or avoid particular features. In moccasin, you can only set the EVM version directly in your Vyper smart contract using a source code pragma, as compiler arguments are not supported.

Adding the following pragma to a contract indicates that it should be compiled for the “prague” fork of the EVM:

# pragma evm-version prague

The EVM version must be set on the Vyper smart contract itself using this pragma syntax.

For more information about pragmas, see the Vyper documentation.