Setting workspace = true in patch.crates-io causes panic

[Aphoh]

Problem

I was trying to take some shortcuts in pinning dependency versions for a project by setting workspace.dependencies and then patching each crate to read from the workspace by setting workspace = true. Repro here. Causes this panic on the latest nightly:

thread 'main' panicked at 'internal error: entered unreachable code', src/tools/cargo/src/cargo/util/toml/mod.rs:2509:45
stack backtrace:
   0: _rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: <cargo::util::toml::TomlDependency>::to_dependency
   4: <core::iter::adapters::map::Map<alloc::collections::btree::map::Iter<alloc::string::String, cargo::util::toml::TomlDependency>, <cargo::util::toml::TomlManifest>::patch::{closure#2}> as core::iter::traits::iterator::Iterator>::try_fold::<(), <core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<alloc::collections::btree::map::Iter<alloc::string::String, cargo::util::toml::TomlDependency>, <cargo::util::toml::TomlManifest>::patch::{closure#2}>, core::result::Result<core::convert::Infallible, anyhow::Error>> as core::iter::traits::iterator::Iterator>::try_fold<(), core::iter::traits::iterator::Iterator::try_for_each::call<cargo::core::dependency::Dependency, core::ops::control_flow::ControlFlow<cargo::core::dependency::Dependency>, core::ops::control_flow::ControlFlow<cargo::core::dependency::Dependency>::Break>::{closure#0}, core::ops::control_flow::ControlFlow<cargo::core::dependency::Dependency>>::{closure#0}, core::ops::control_flow::ControlFlow<core::ops::control_flow::ControlFlow<cargo::core::dependency::Dependency>>>
   5: <alloc::vec::Vec<cargo::core::dependency::Dependency> as alloc::vec::spec_from_iter::SpecFromIter<cargo::core::dependency::Dependency, core::iter::adapters::GenericShunt<core::iter::adapters::map::Map<alloc::collections::btree::map::Iter<alloc::string::String, cargo::util::toml::TomlDependency>, <cargo::util::toml::TomlManifest>::patch::{closure#2}>, core::result::Result<core::convert::Infallible, anyhow::Error>>>>::from_iter
   6: core::iter::adapters::try_process::<core::iter::adapters::map::Map<alloc::collections::btree::map::Iter<alloc::string::String, cargo::util::toml::TomlDependency>, <cargo::util::toml::TomlManifest>::patch::{closure#2}>, cargo::core::dependency::Dependency, core::result::Result<core::convert::Infallible, anyhow::Error>, <core::result::Result<alloc::vec::Vec<cargo::core::dependency::Dependency>, anyhow::Error> as core::iter::traits::collect::FromIterator<core::result::Result<cargo::core::dependency::Dependency, anyhow::Error>>>::from_iter<core::iter::adapters::map::Map<alloc::collections::btree::map::Iter<alloc::string::String, cargo::util::toml::TomlDependency>, <cargo::util::toml::TomlManifest>::patch::{closure#2}>>::{closure#0}, alloc::vec::Vec<cargo::core::dependency::Dependency>>
   7: <cargo::util::toml::TomlManifest>::patch
   8: cargo::util::toml::read_manifest_from_str
   9: cargo::util::toml::read_manifest
  10: <cargo::core::workspace::Packages>::load
  11: <cargo::core::workspace::Workspace>::find_root
  12: <cargo::core::workspace::Workspace>::new
  13: <clap::parser::matches::arg_matches::ArgMatches as cargo::util::command_prelude::ArgMatchesExt>::workspace
  14: cargo::commands::test::exec
  15: cargo::cli::main
  16: cargo::main

Steps

1. Take any project and put a.workspace = true in the [patch.crates-io]

Possible Solution(s)

Just throw an error saying this is unsupported? It might be useful if it was supported though.

Notes

No response

Version

cargo 1.68.0-nightly (2381cbdb4 2022-12-23)
release: 1.68.0-nightly
commit-hash: 2381cbdb4e9b07090f552d34a44a529b6e620e44
commit-date: 2022-12-23
host: aarch64-apple-darwin
libgit2: 1.5.0 (sys:0.15.0 vendored)
libcurl: 7.84.0 (sys:0.4.59+curl-7.86.0 system ssl:(SecureTransport) LibreSSL/3.3.6)
os: Mac OS 13.0.1 [64-bit]

[Muscraft]

Using dependencies from [workspace.dependencies] for [patch] was never supposed to be supported. The problem comes from adding Workspace to TomlDependency. This made it so that anything that had the type TomlDependency could inherit from [workspace.dependencies] i.e. [patch] and [replace].

It was an oversight on my part during implementation. Work on #11409 actually brought this to my attention, and I was hoping no one would run into it before I had time to fix it. I need to get #11409 merged before a fix for this can be implemented. I have a general idea of what needs to happen after #11409, so hopefully, it won't be too long to fix this issue.

All of that being said can you expand on what you are trying to do and what using [workspace.dependencies] and [patch] solves?