Build requires cargo-libbpf installed

Something's wrong with the libbpf-cargo dependency: cargo build on a F38 box fails with:

error: failed to run custom build command for `udev-hid-bpf v0.1.0 (/home/whot/code/udev-hid-bpf)`

Caused by:
  process didn't exit successfully: `/home/whot/code/udev-hid-bpf/target/debug/build/udev-hid-bpf-b0861b9859995480/build-script-build` (exit status: 101)
  --- stdout
  cargo:rerun-if-changed=./src/bpf/
  cargo:rerun-if-changed=./src/hid_bpf_wrapper.h

  --- stderr
  Warning: unrecognized map: license
  Warning: unrecognized map: version
  Warning: unrecognized map: .ksyms
  error: no such command: `libbpf`

  	View all installed commands with `cargo --list`
  thread 'main' panicked at 'Failed to remove BPF object in ./target/bpf/attach.bpf.o: Os { code: 2, kind: NotFound, message: "No such file or directory" }', build.rs:34:33
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

This is with a few printfs added for better errors. Note the no such command: libbpf which weirdly doesn't cause the Command::new()... to fail. The actual failure is during fs.remove_file().

Installing the Fedora libbpf-cargo gets past this point so it looks like there's an issue with setting up the $PATH correctly, or maybe we need to use the SkeletonBuilder API (see the docs).

Admin message

Build requires cargo-libbpf installed