flutter-app-template not building on macos, failed due to #[cfg(doctest)]

[modulovalue]

Following the steps in the readme and trying to run the default template on macos leads to:

... cargo flutter run
flutter build bundle lib/main.dart
   Compiling xml-rs v0.8.2
   Compiling strsim v0.8.0
   Compiling block v0.1.6
   Compiling vec_map v0.8.1
   Compiling scopeguard v1.1.0
   Compiling bindgen v0.52.0
   Compiling syn v1.0.17
   Compiling lazycell v1.2.1
   Compiling rustc-hash v1.1.0
   Compiling foreign-types-shared v0.1.1
   Compiling shlex v0.1.1
   Compiling peeking_take_while v0.1.2
   Compiling serde v1.0.106
   Compiling ryu v1.0.3
   Compiling smallvec v1.3.0
   Compiling tinystr v0.3.2
error[E0658]: `cfg(doctest)` is experimental and subject to change
 --> /Users/valauskasmodestas/.cargo/registry/src/github.com-1ecc6299db9ec823/xml-rs-0.8.2/src/lib.rs:9:7
  |
9 | #[cfg(doctest)]
  |       ^^^^^^^
  |
  = note: for more information, see https://github.com/rust-lang/rust/issues/62210

error[E0658]: `cfg(doctest)` is experimental and subject to change
  --> /Users/valauskasmodestas/.cargo/registry/src/github.com-1ecc6299db9ec823/xml-rs-0.8.2/src/lib.rs:13:7
   |
13 | #[cfg(doctest)]
   |       ^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/62210

   Compiling core-video-sys v0.1.3
   Compiling take_mut v0.2.2
   Compiling slab v0.4.2
   Compiling itoa v0.4.5
   Compiling dispatch v0.1.4
   Compiling instant v0.1.2
   Compiling futures-core v0.3.4
   Compiling futures-timer v2.0.2
   Compiling futures-io v0.3.4
   Compiling pin-project-lite v0.1.4
   Compiling pin-utils v0.1.0-alpha.4
   Compiling once_cell v1.3.1
   Compiling futures-task v0.3.4
   Compiling libc v0.2.68
   Compiling log v0.4.8
   Compiling memchr v2.3.3
   Compiling bitflags v1.2.1
   Compiling proc-macro2 v1.0.10
   Compiling khronos_api v3.1.0
   Compiling nom v4.2.3
   Compiling clang-sys v0.28.1
   Compiling libloading v0.5.2
   Compiling thread_local v1.0.1
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0658`.
error: could not compile `xml-rs`.
warning: build failed, waiting for other jobs to finish...
error: build failed
This is taking longer than expected...

[dvc94ch]

What rust version are you using? The build is failing with xml-rs. Update rust and try again...