Inherited Enum Allows Type Reference but Not Value Access

[zzh1996]

Description

When an enum is defined in a parent contract and a child contract inherits from it, the child contract correctly recognizes the enum type but cannot directly access its values. This behavior is inconsistent and unexpected.

Environment

• Compiler version: 0.8.28
• Compilation pipeline (legacy, IR, EOF): default
• Target EVM version (as per compiler settings): default
• Framework/IDE (e.g. Foundry, Hardhat, Remix): Remix IDE

Steps to Reproduce

// SPDX-License-Identifier: UNLICENSED
pragma solidity =0.8.28;

contract A {
    enum E { E1 }
}

contract B is A {
}

contract C {
    A.E e1 = A.E.E1; // ✅ OK
    B.E e2 = A.E.E1; // ✅ OK
    B.E e3 = B.E.E1; // ❌ TypeError: Member "E" not found or not visible after argument-dependent lookup in type(contract B).
}