nightly builds failing in `proc-macro2` 1.0.56 crate

[Robert Collins]

This is not a direct dependency.

$ cargo tree -i proc-macro2
proc-macro2 v1.0.56
├── quote v1.0.26
│   ├── syn v1.0.109
│   │   └── test-log v0.2.11 (proc-macro)
│   │       [dev-dependencies]
│   │       └── fs_at v0.1.9 (C:\Users\robertc\Documents\src\fs_at)
│   └── test-log v0.2.11 (proc-macro) (*)
├── syn v1.0.109 (*)
└── test-log v0.2.11 (proc-macro) (*)

So this doesn't affect users on nightly, but we can't test on nightly at the moment.

  Running `/home/runner/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/rustc --crate-name proc_macro2 --edition=2018 /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.56/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no --cfg 'feature="default"' --cfg 'feature="proc-macro"' -C metadata=516e696159394256 -C extra-filename=-516e696159394256 --out-dir /home/runner/work/fs_at/fs_at/target/debug/deps -L dependency=/home/runner/work/fs_at/fs_at/target/debug/deps --extern unicode_ident=/home/runner/work/fs_at/fs_at/target/debug/deps/libunicode_ident-3357ee1867c8a168.rmeta --cap-lints allow --cfg use_proc_macro --cfg wrap_proc_macro --cfg proc_macro_span`
error[E0635]: unknown feature `proc_macro_span_shrink`
  --> /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.56/src/lib.rs:92:30
   |
92 |     feature(proc_macro_span, proc_macro_span_shrink)
   |                              ^^^^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0635`.
error: could not compile `proc-macro2` (lib) due to previous error

Caused by:

[Robert Collins]

Fixed in test-log 0.2.12, will update lockfile accordingly.