[Libguestfs] Cargo edition problem with Debian 11

https://gitlab.com/nbdkit/nbdkit/-/jobs/3598390121 ---------------------------------------------------------------------- cargo build --release --example ramdisk Downloading crates ... Downloaded float-cmp v0.9.0 Downloaded downcast v0.11.0 Downloaded mockall_derive v0.11.3 Downloaded itertools v0.10.5 Downloaded aho-corasick v0.7.20 Downloaded predicates-tree v1.0.7 error: failed to parse manifest at `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/predicates-tree-1.0.7/Cargo.toml` Caused by: failed to parse the `edition` key Caused by: this version of Cargo is older than the `2021` edition, and only supports `2015` and `2018` editions. ---------------------------------------------------------------------- nbdkit itself uses edition = 2018, but this seems to affects one of the dependencies. I'm not sure how to solve this, but one ideas I had is in ./configure to check if the cargo/rust we're trying to use doesn't support some base edition (eg. latest edition supported < 2021) then we would disable rust bindings. Unfortunately actually getting the latest supported edition seems hard. The best I could find is parsing this which doesn't seem ideal: $ rustc --help |& grep -- --edition --edition 2015|2018|2021|2024 What do you think? Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org