Cargo: use of unstable library feature 'scoped

I have this repo cloned on my Ubuntu 22.04 instance: https://gitlab.conclusive.pl/devices/ubuntu-build

and I'm trying to run:

git submodule update --init --recursive
sudo make image PROFILE=kstr-sama5d27

I receive the following error:

error[E0658]: use of unstable library feature 'scoped_threads' --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/cargo-deb-1.41.3/src/data.rs:128:5 | 128 | std::thread::scope(move |s| { | ^^^^^^^^^^^^^^^^^^ | = note: see issue #93203 https://github.com/rust-lang/rust/issues/93203 for more information

error[E0658]: use of unstable library feature 'scoped_threads' --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/cargo-deb-1.41.3/src/data.rs:130:29 | 130 | let hash_thread = s.spawn(move || { | ^^^^^ | = note: see issue #93203 https://github.com/rust-lang/rust/issues/93203 for more information

error[E0658]: use of unstable library feature 'scoped_threads' --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/cargo-deb-1.41.3/src/data.rs:162:24 | 162 | Ok(hash_thread.join().unwrap()) | ^^^^ | = note: see issue #93203 https://github.com/rust-lang/rust/issues/93203 for more information

For more information about this error, try rustc --explain E0658. error: could not compile cargo-deb due to 3 previous errors warning: build failed, waiting for other jobs to finish... error: failed to compile gpt-manipulator v0.1.0 (/home/davidg/kstr-ubuntu-build/build-kstr-sama5d27/gpt-manipulator), intermediate artifacts can be found at /home/davidg/kstr-ubuntu-build/build-kstr-sama5d27/gpt-manipulator/target make: *** [Makefile:106: gpt-manipulator] Error 101

There's been no change to the source code since the last time this worked so my suspicion is something external has changed. I performed grep -r "thread::scope" . in the repo and found no uses of this unstable feature.

The gpt-manipulator submodule repo having the build error is https://gitlab.conclusive.pl/devices/gpt-manipulator and I can cargo build from this repo without issue.

Note that my environment is prepared using sudo apt-get install bc libssl-dev cargo gdisk mtools. This installs rust&cargo system-wide and allows sudo to access it (needed by sudo make image). I read that using rustup install method I can switch to nightly and allow the unstable feature but installing this way sudo can't find the binaries.

cargo --version and rustc --version both report 1.61.0

How can I successfully build this?

CodePudding user response：

Scoped threads have been stabilized in 1.63 so some dependency might be using it now. If you're running an earlier compiler it will complain about that usage though. A rustup update or the equivalent for what you use to update Rust should fix this.

CodePudding user response：

The command that's failing is actually cargo install cargo-deb. It appears the latest version uses scoped threads.

As a workaround, you can install a specific older version:

cargo install cargo-deb --version 1.28.2

Might want to use 1.28.2 to match the version you say is in Cargo.toml, otherwise it looks like 1.40.5 is the last version not using std::thread::scope.

CodePudding user response：

Per @cafce25's answer, scoped threads are stabilized in 1.63.0, however at present apt is limited to supplying 1.61.0.

To obtain a version >= 1.63.0 that can be run with sudo:

curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf | sudo sh
append secure_path in /etc/sudoers with :/root/.cargo/bin