1 error: macro requires a cfg-pattern as an argument
5 | ^^^^^^^ cfg-pattern required
7 = note: this error originates in the macro `cfg` (in Nightly builds, run with -Z macro-backtrace for more info)
9 error: expected identifier, found `123`
13 | ^^^ expected identifier
15 error[E0565]: literal in `cfg` predicate value must be a string
21 error: aborting due to 3 previous errors
23 For more information about this error, try `rustc --explain E0565`.