cargo metadata panics when you have a dependency to a bin crate #5548
Description
Steps to reproduce:
cargo new --bin foo
cargo new --lib bar
cd bar
echo 'foo = { path = "../foo" }' >> Cargo.toml
cargo metadata --format-version=1
Output:
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', libcore/option.rs:335:21
stack backtrace:
0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: std::sys_common::backtrace::print
at libstd/sys_common/backtrace.rs:71
at libstd/sys_common/backtrace.rs:59
2: std::panicking::default_hook::{{closure}}
at libstd/panicking.rs:211
3: std::panicking::default_hook
at libstd/panicking.rs:227
4: std::panicking::rust_panic_with_hook
at libstd/panicking.rs:463
5: std::panicking::begin_panic_fmt
at libstd/panicking.rs:350
6: rust_begin_unwind
at libstd/panicking.rs:328
7: core::panicking::panic_fmt
at libcore/panicking.rs:71
8: core::panicking::panic
at libcore/panicking.rs:51
9: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once
10: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter
11: core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &'a mut F>::call_once
12: <alloc::vec::Vec<T> as alloc::vec::SpecExtend<T, I>>::from_iter
13: cargo::ops::cargo_output_metadata::output_metadata
14: cargo::commands::metadata::exec
15: cargo::cli::main
16: cargo::main
17: std::rt::lang_start::{{closure}}
18: std::panicking::try::do_call
at libstd/rt.rs:59
at libstd/panicking.rs:310
19: __rust_maybe_catch_panic
at libpanic_unwind/lib.rs:105
20: std::rt::lang_start_internal
at libstd/panicking.rs:289
at libstd/panic.rs:374
at libstd/rt.rs:58
21: main
22: __libc_start_main
23: <unknown>
This is a regression - on stable it works and returns valid metadata.
cargo 1.27.0-nightly (9e53ac6 2018-05-07)
rustc 1.27.0-nightly (2f2a11dfc 2018-05-16)