rustBoot Book's commands for compiling rpi4 fail with "critical-section" selection error because versions have been yanked from crates.io

[jwmurray]

I am hitting an error because the several releases of the critical-section crate have been pulled from crates.io (versions 0.2.5 - 0.2.8).

When I attempt to compile the rpi4 rustBoot as shown below with cargo rpi4 build rustBoot-only per the rustBoot book, the system cannot resolve the critical-section crate.

Steps to reproduce on macos 15.3.1 and Ubuntu 24.10

git clone git@github.com:nihalpasham/rustBoot.git && cd rustBoot

echo "    arm_64bit=1
      enable_uart=1
      init_uart_clock=4000000
      kernel=rustBoot.bin
  " > config.txt

rustup default nightly
rustup target add aarch64-unknown-none-softfloat

cargo install cargo-binutils
rustup component add llvm-tools-preview

rustup show

Default host: aarch64-apple-darwin
rustup home:  /Users/jmurray/.rustup

installed toolchains
--------------------
stable-aarch64-apple-darwin
nightly-aarch64-apple-darwin (active, default)
1.81-aarch64-apple-darwin

active toolchain
----------------
name: nightly-aarch64-apple-darwin
active because: it's the default toolchain
installed targets:
  aarch64-apple-darwin
  aarch64-apple-ios-sim
  aarch64-unknown-linux-gnu
  aarch64-unknown-none-softfloat
  thumbv6m-none-eabi
  wasm32-unknown-unknown
  x86_64-unknown-linux-gnu

The failing output is from this command cargo rpi4 build rustBoot-only. I have removed 60 warning messages from the output.

I have not been able to resolve the critical-section crate failures.

~ cargo rpi4 build rustBoot-only
   Compiling typenum v1.18.0
   Compiling generic-array v0.14.7
   Compiling subtle v2.4.1
   Compiling rand_core v0.6.4
   Compiling const-oid v0.7.1
   Compiling zeroize v1.4.3
   Compiling libc v0.2.170
...

warning: `xtask` (bin "xtask") generated 60 warnings
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.63s
     Running `target/debug/xtask rpi4 build rustBoot-only`
$ cargo build --release
    Updating crates.io index
error: failed to select a version for the requirement `critical-section = "^0.2.5"`
  version 0.2.5 is yanked
  version 0.2.6 is yanked
  version 0.2.7 is yanked
  version 0.2.8 is yanked
location searched: crates.io index
required by package `defmt-rtt v0.3.2`
    ... which satisfies dependency `defmt-rtt = "^0.3.2"` of package `stm32f746_bootfw v0.1.0 (/home/jmurray/code/rust/rustBoot/boards/firmware/stm32f746/boot_fw_blinky_green)`
Error: command `cargo build --release` failed, exit status: 101