One of tests is broken

[ignatenkobrain]

[  101s] ---- src/cfg.rs - if_cfg (line 54) stdout ----
[  101s] error: unexpected end of macro invocation
[  101s]  --> src/cfg.rs:59:2
[  101s]   |
[  101s] 6 | })
[  101s]   |  ^ missing tokens in macro arguments
[  101s] 
[  101s] error: aborting due to previous error
[  101s] 
[  101s] Couldn't compile the test.
[  101s] 
[  101s] failures:
[  101s]     src/cfg.rs - if_cfg (line 54)

[cuviper]

I believe this is a consequence of a change to meta parsing that became stable in Rust 1.40.
rust-lang/rust#63674

rust-mac/src/cfg.rs

Lines 56 to 59 in 66afc66

	/// # fn main() {
	/// if_cfg!(test {
	/// println!("Crate built as a test suite");
	/// })

So the whole test { ... } now gets consumed by the $cfg:meta matcher, and then the macro thinks it's missing the $t:block.

There was a crater run for that Rust change which showed 0 regressions. However, the mac crate was masked because of existing errors from deny(warnings):

[INFO] [stderr]     Checking mac v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr] error: `...` range patterns are deprecated
[INFO] [stderr]   --> src/matches.rs:42:41
[INFO] [stderr]    |
[INFO] [stderr] 42 |         matches!(bar.as_bytes()[1], b'0'... b'9')
[INFO] [stderr]    |                                         ^^^ help: use `..=` for an inclusive range
[INFO] [stderr]    |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]   --> src/lib.rs:1:24
[INFO] [stderr]    |
[INFO] [stderr] 1  | #![cfg_attr(test, deny(warnings))]
[INFO] [stderr]    |                        ^^^^^^^^
[INFO] [stderr]    = note: `#[deny(ellipsis_inclusive_range_patterns)]` implied by `#[deny(warnings)]`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `mac`.

I'll note this upstream for posterity, but I'm sure it's too late to fix this.

If you care to change syntax, maybe you can use a separator like $cfg:meta => $t:block.