TypeScript 4.4 breaks building yargs

[ansgarm]

Hi!

TypeScript 4.4 was released 4 days ago and introduced the following:

try {
    executeSomeThirdPartyCode();
}
catch (err) { // err: unknown

    // Error! Property 'message' does not exist on type 'unknown'.
    console.error(err.message);

    // Works! We can narrow 'err' from 'unknown' to 'Error'.
    if (err instanceof Error) {
        console.error(err.message);
    }
}

This breaks the build of yargs (there is no package-lock.json, which seems to be on purpose):

lib/argsert.ts:76:18 - error TS2571: Object is of type 'unknown'.

76     console.warn(err.stack);
                    ~~~

lib/utils/maybe-async-result.ts:22:25 - error TS2345: Argument of type 'unknown' is not assignable to parameter of type 'Error'.

22     return errorHandler(err);
                           ~~~

Found 2 errors.