panic on cyclical dev-dependency with missing feature

[ehuss]

Problem

A cyclical dev-dependency with a missing feature causes a panic:

thread 'main' panicked at src/cargo/util/graph.rs:149:20:
the only path was a cycle, no dependency graph has this shape
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::option::expect_failed
   3: <cargo::util::graph::Graph<cargo::core::package_id::PackageId, im_rc::hash::set::HashSet<cargo::core::dependency::Dependency>>>::path_to::<<cargo::util::graph::Graph<cargo::core::package_id::PackageId, im_rc::hash::set::HashSet<cargo::core::dependency::Dependency>>>::path_to_bottom::{closure#0}, core::iter::adapters::flatten::FlatMap<core::option::IntoIter<&im_rc::ord::map::OrdMap<cargo::core::package_id::PackageId, im_rc::hash::set::HashSet<cargo::core::dependency::Dependency>>>, im_rc::ord::map::Iter<cargo::core::package_id::PackageId, im_rc::hash::set::HashSet<cargo::core::dependency::Dependency>>, <cargo::util::graph::Graph<cargo::core::package_id::PackageId, im_rc::hash::set::HashSet<cargo::core::dependency::Dependency>>>::edges::{closure#0}>>
   4: cargo::core::resolver::errors::describe_path_in_context
   5: cargo::core::resolver::errors::activation_error
   6: cargo::core::resolver::activate_deps_loop
   7: cargo::core::resolver::resolve
   8: cargo::ops::resolve::resolve_with_previous
   9: cargo::ops::cargo_generate_lockfile::generate_lockfile
  10: cargo::commands::generate_lockfile::exec
  11: cargo::cli::main
  12: cargo::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Steps

A test using cargo's test infrastructure:

#[cargo_test]
fn cyclical_dep_with_missing_feature() {
    // Checks for error handling when a cyclical dev-dependency specify a
    // feature that doesn't exist.
    let p = project()
        .file(
            "Cargo.toml",
            r#"
                [package]
                name = "foo"
                version = "0.1.0"

                [dev-dependencies]
                foo = { path = ".", features = ["missing"] }
            "#,
        )
        .file("src/lib.rs", "")
        .build();
    p.cargo("check")
        .with_status(101)
        .with_stderr("ENTER CORRECT ERROR HERE")
        .run();
}

Possible Solution(s)

I'm not sure.

Notes

No response

Version

cargo 1.75.0-nightly (b4d18d4bd 2023-10-31)
release: 1.75.0-nightly
commit-hash: b4d18d4bd3db6d872892f6c87c51a02999b80802
commit-date: 2023-10-31
host: aarch64-apple-darwin
libgit2: 1.7.1 (sys:0.18.1 vendored)
libcurl: 8.1.2 (sys:0.4.68+curl-8.4.0 system ssl:(SecureTransport) LibreSSL/3.3.6)
ssl: OpenSSL 1.1.1u  30 May 2023
os: Mac OS 14.0.0 [64-bit]

[Eh2406]

Investigating now. By the way, how did you come across this?

[ehuss]

By the way, how did you come across this?

I was just testing something for some other issue, and forgot to put in the [features] table, and hit the panic.