ICE: found unstable fingerprints for predicates_of(core[b0ed]::convert::From) #85039
Description
I think this is an incremental compilation error based on similar issues and the fact that I couldn't get this to happen again, but I figured I'd still report it.
❯ cargo c
Compiling faux_macros v0.1.1 (/home/coolreader18/dwelo/faux/faux_macros)
thread 'rustc' panicked at 'found unstable fingerprints for predicates_of(core[b0ed]::convert::From): GenericPredicates { parent: None, predicates: [(Binder(TraitPredicate(<Self as std::marker::Sized>)), /home/coolreader18/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:20: 365:25 (#0)), (Binder(TraitPredicate(<T as std::marker::Sized>)), /home/coolreader18/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:16: 365:17 (#0)), (Binder(TraitPredicate(<Self as std::convert::From<T>>)), /home/coolreader18/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/convert/mod.rs:365:1: 365:25 (#0))] }', /rustc/88f19c6dab716c6281af7602e30f413e809c5974/compiler/rustc_query_system/src/query/plumbing.rs:593:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: rustc 1.52.0 (88f19c6da 2021-05-03) running on x86_64-unknown-linux-gnu
note: compiler flags: -C prefer-dynamic -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type proc-macro
note: some of the compiler flags provided by cargo are hidden
query stack during panic:
#0 [predicates_of] computing predicates of `std::convert::From`
#1 [check_item_well_formed] checking that `create::<impl at faux_macros/src/create.rs:50:1: 69:2>` is well-formed
end of query stack
error: could not compile `faux_macros`
And here's the snapshot of what I was working on when it happened: https://github.com/coolreader18/faux/tree/ice-repro
Sorry I can't give more info 😞