Rustc panics when running on a workspace

[sezna]

I am not really sure what is causing this so I'm going to provide as much detail as I can. I'm using cargo-udeps in a workspace with ~15 crates on 1.44 nightly. The workspace contains 3 proc macro crates. All three of those proc macro crates fail to compile in cargo-udeps, but not with a regular cargo build, with this error:

error: internal compiler error: cannot lex `source_file` without source: /home/alex/.cargo/registry/src/github.com-1ecc6299db9ec823/quote-1.0.3/src/lib.rs

thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:880:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.44.0-nightly (f509b26a7 2020-03-18) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z save-analysis -C prefer-dynamic -C debuginfo=2 -C incremental --crate-type proc-macro

note: some of the compiler flags provided by cargo are hidden

error: aborting due to previous error

So, it seems that perhaps the quote dependency inside of the proc macros in the workspace is triggering it?

Anyway, if I can provide any more detail, please let me know. This tool is great and I am torn by temporarily not being able to use it. :smile:

[est31]

I can run cargo-udeps on git checkouts of the quote and failure crates just fine, where failure depends on a proc macro crate that uses quote. I'm not sure how to reproduce it. I remember running into it myself but can't remember on which project.

[est31]

A minimal reproducible example, or just any example, would be of great help.

[sezna]

Sure thing. Our workspace is pretty hairy, I'll try to pare it down and put something together today.

[est31]

Likely this isn't due to cargo-udeps but a bug in save analysis creation.

I've recently added a backend not based on save analysis but on binary dep depinfo.

@sezna could you install latest cargo-udeps master (cargo install --locked --git https://github.com/est31/cargo-udeps) and run cargo udeps --backend depinfo? Does that work? Also cc @lovesegfault as he reported problems with current cargo-udeps as well.

[lovesegfault]

I'll try and repro my issue again; it had happened as I attempted to move my company to a new nightly, and then we encountered an ICE in the cargo-udeps step of our CI.

I will attempt a bump again in the coming weeks, if I find the issue I'll report back with more details :)

[est31]

I'll close this, as the save-analysis backend is in the process of removal. If an ICE occurs again, please write or open a new issue. Thanks!