Foundry "failed to resolve versions"

[ThatOneCalculator]

Honestly, this error is not very descriptive, so I'm not sure what exactly this error is about. These are all Vyper contracts with # @version ^0.4.0

| 'forge' returned non-zero exit code 1
| 2024-07-23T22:16:28.238665Z ERROR foundry_compilers::resolver: failed to resolve versions
| Error:
| stderr: Found incompatible Solidity versions:
| stderr: contracts/REDACTED.vy  imports:
| stderr: Found incompatible Solidity versions:
| stderr: contracts/REDACTED.vy  imports:
| stderr: Found incompatible Solidity versions:
| stderr: contracts/REDACTED.vy  imports:
| stderr: Found incompatible Solidity versions:
| stderr: contracts/REDACTED.vy  imports:
| ERROR:Slither:Unable to compile all targets.