Can't disable a clang-tidy warning

I have this, which causes no warnings, either in the IDE or when compiled:

    string rtext;

    int out_len1 = 1;
    int out_len2 = 1;
    int out_len = out_len1 + out_len2;
    rtext.resize(static_cast<unsigned long>(out_len));

But when I remove the intermediate variable:

    rtext.resize(static_cast<unsigned long>(out_len1 + out_len2));

... the IDE pops up a Clang-tidy warning "Clang-Tidy: Either cast from 'int' to 'unsigned long' is ineffective, or there is loss of precision before the conversion".

So no problem, I follow the suggestion light bulb and suppress the warning:

    rtext.resize(static_cast<unsigned long>(out_len1 + out_len2)); // NOLINT(bugprone-misplaced-widening-cast)

This stops the IDE warning, but when I commit the code with Git, with "Perform code analysis" enabled, I still get (the same) warning.

Is there some Clang-tidy option I missed here, or is this a bug?

Thanks.

 -Guy