error: at least one tag is required: #[test_tag::tag(<tags...>)]
 --> tests/fail/missing-tag-1.rs:5:1
  |
5 | #[test_tag::tag]
  | ^^^^^^^^^^^^^^^^
  |
  = note: this error originates in the attribute macro `test_tag::tag` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0601]: `main` function not found in crate `$CRATE`
 --> tests/fail/missing-tag-1.rs:7:21
  |
7 | fn cant_compile() {}
  |                     ^ consider adding a `main` function to `$DIR/tests/fail/missing-tag-1.rs`