int main() {
    const int i{0};
    int& ref{i};
    return 0;
}


The above code produces the error message:

error: binding value of type 'void' to reference to type 'int' drops <<ERROR>> qualifiers
    int& ref{f.value};
         ^  ~~~~~~~~~

While the following produces the correct error message:

int main() {
    const int i{0};
    int& ref = i;
    return 0;
}

error: binding value of type 'const int' to reference to type 'int' drops 'const' qualifier
    int& ref = i;

Brace-initialization seems to cause an error in the error reporting, unable to access the correct types for the message to display. I'm not familiar with clang internals so I'm not much help here.