Cannot compile on nightly-2022-01-13 - target_has_atomic is experimental

[koxu1996]

Problem description

I was trying to use serde package with nightly-2022-01-13 toolchain, but I got compilation errors like the following one:

   Compiling serde v1.0.152
error[E0658]: `cfg(target_has_atomic)` is experimental and subject to change
   --> /home/koxu1996/.cargo/registry/src/github.com-1ecc6299db9ec823/serde-1.0.152/src/lib.rs:258:59
    |
258 |     #[cfg(all(feature = "std", not(no_target_has_atomic), target_has_atomic = "8"))]
    |                                                           ^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: see issue #32976 <https://github.com/rust-lang/rust/issues/32976> for more information
    = help: add `#![feature(cfg_target_has_atomic)]` to the crate attributes to enable

I am aware this is outdated nightly toolchain, but should we expect some compatibility here 🤔? If not, please close the issue.

Reproducing

1. Create simple project with serde:

➜  cargo new app --bin && cd ./app
     Created binary (application) `app` package
➜  cargo add serde
    Updating crates.io index
      Adding serde v1.0.152 to dependencies.
             Features:
             + std
             - alloc
             - derive
             - rc
             - serde_derive
             - unstable
➜  cargo build

2. Switch to nightly-2022-01-13 toolchain:

➜  rustup default nightly-2022-01-13

info: using existing install for 'nightly-2022-01-13-x86_64-unknown-linux-gnu'
info: default toolchain set to 'nightly-2022-01-13-x86_64-unknown-linux-gnu'

  nightly-2022-01-13-x86_64-unknown-linux-gnu unchanged - rustc 1.60.0-nightly (1bd4fdc94 2022-01-12)

3. Build:

➜  cargo build

Workaround

Use nightly-2022-04-07 toolchain or serde <= 1.0.149 (before #2337).

[dtolnay]

Old nightly toolchains are not supported. The expectation if you are using nightly is that you are updating every night, or only using crate versions from the same time frame as the nightly.