Misleading error in println!/format! invocation

[yuriks]

The expression println!(format!("test")) produces the following error:

<anon>:18:18: 18:24 error: macro undefined: 'format'
<anon>:18         println!(format!("test"))
                           ^~~~~~
<anon>:18:18: 18:33 error: format argument must be a string literal.
<anon>:18         println!(format!("test"))
                           ^~~~~~~~~~~~~~~
error: aborting due to 2 previous errors

The macro undefined: 'format' error is pretty misleading, implying that the user mispelled format! or that it has a different name, but in reality it's just complaining because you're supposed to pass a literal to println!. Why does this error get generated and is there a way to make it clearer?

[huonw]

Seems to be a bug in how our macros are resolved. Dupe of #12404.

I'll copy the example here to that one though, since that bug doesn't really state what's up very clearly. (Thanks for filing.)