Deserialisation regression in nightly

[nataziel]

I noticed a CI failure in pubgrub, and was able to reproduce locally by cloning the repo and running the tests with nightly via cargo +nightly test --all-features --workspace. The error occurs whether or not you do the -Zminimal-versions shenanigans from the CI workflow, so that is unrelated.

Test output

---- tests::serde_round_trip stdout ----

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 44 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 34 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 45 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 45 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 44 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 34 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 44 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 34 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 34 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 34 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 33 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 33 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 33 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 32 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 32 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 32 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 31 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 31 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 31 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 31 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 30 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 30 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 30 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 29 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 29 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 29 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 28 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 28 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 28 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 28 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 27 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 27 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 27 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 26 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 26 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 26 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1232:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }

thread 'tests::serde_round_trip' (1292) panicked at version-ranges\src\lib.rs:1224:5:
Test failed: called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }.
minimal failing input: range = Ranges {
    segments: [
        (
            Excluded(
                0,
            ),
            Unbounded,
        ),
    ],
}
        successes: 0
        local rejects: 0
        global rejects: 0



failures:
    tests::minimal_test
    tests::serde_round_trip

test result: FAILED. 29 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.08s

error: test failed, to rerun pass `-p version-ranges --lib`

You should be able to (slightly more) minimally reproduce the error with:

    #[test]
    fn minimal_test() {
        let segments = smallvec![(Excluded(0u32), Unbounded)];
        let ranges = Ranges { segments };
        let s = ron::ser::to_string(&ranges).unwrap();
        let test_string = "[(Excluded(0),Unbounded)]";

        assert_eq!(test_string, s);

        let r = ron::de::from_str(test_string).unwrap();
        assert_eq!(ranges, r)
    }

I did some investigating with cargo bisect-rustc, finding this commit. There appears to be some problem with deserialisation, potentially related to lifetimes, but my rust knowledge isn't good enough to work out why. Bisection output when run in the root directory of pubgrub is as follows:

searched nightlies: from nightly-2025-01-01 to nightly-2025-08-20
regressed nightly: nightly-2025-08-18
searched commit range: 2e2642e...425a9c0
regressed commit: 425a9c0

bisected with cargo-bisect-rustc v0.6.10

Host triple: x86_64-pc-windows-msvc
Reproduce with:

cargo bisect-rustc --start=2025-01-01 --end=2025-08-20 --script=C:\Users\me\AppData\Local\Programs\Git\usr\bin\bash.exe -- ./test.sh

where test.sh is:

#!/bin/bash

cargo test --all-features --workspace

I expected to see this happen: The tests pass

Instead, this happened: The tests fail

Backtrace

thread 'tests::serde_round_trip' (12732) panicked at version-ranges\src\lib.rs:1219:43:
called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }
stack backtrace:
   0:     0x7ff70ae918d2 - std::backtrace_rs::backtrace::win64::trace
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\..\..\backtrace\src\backtrace\win64.rs:85
   1:     0x7ff70ae918d2 - std::backtrace_rs::backtrace::trace_unsynchronized
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\..\..\backtrace\src\backtrace\mod.rs:66
   2:     0x7ff70ae918d2 - std::sys::backtrace::_print_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:66
   3:     0x7ff70ae918d2 - std::sys::backtrace::impl$0::print::impl$0::fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:39
   4:     0x7ff70ae9bbda - core::fmt::rt::Argument::fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\fmt\rt.rs:173
   5:     0x7ff70ae9bbda - core::fmt::write
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\fmt\mod.rs:1468
   6:     0x7ff70ae6f737 - std::io::default_write_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\io\mod.rs:639
   7:     0x7ff70ae6f737 - std::io::Write::write_fmt<alloc::vec::Vec<u8,alloc::alloc::Global> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\io\mod.rs:1954
   8:     0x7ff70ae7fb75 - std::sys::backtrace::BacktraceLock::print
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:42
   9:     0x7ff70ae843c9 - std::panicking::default_hook::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:301
  10:     0x7ff70ae841f3 - std::panicking::default_hook
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:325
  11:     0x7ff70adc0709 - alloc::boxed::impl$31::call
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1999
  12:     0x7ff70adc0709 - test::test_main_with_exit_callback::closure$0<test::test_main::closure_env$0>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:145
  13:     0x7ff70ae84bca - std::panicking::panic_with_hook
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:842
  14:     0x7ff70ae84a19 - std::panicking::panic_handler::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:707
  15:     0x7ff70ae7fd7f - std::sys::backtrace::__rust_end_short_backtrace<std::panicking::panic_handler::closure_env$0,never$>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:174
  16:     0x7ff70ae6c65e - std::panicking::panic_handler
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:698
  17:     0x7ff70aeaa2d1 - core::panicking::panic_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\panicking.rs:75
  18:     0x7ff70aea9c80 - core::result::unwrap_failed
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\result.rs:1852
  19:     0x7ff70ad37ac1 - enum2$<core::result::Result<version_ranges::Ranges<u32>,ron::error::SpannedError> >::unwrap
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\core\src\result.rs:1223
  20:     0x7ff70ad37ac1 - version_ranges::tests::serde_round_trip::closure$1
                               at C:\Users\me\git\rust\pubgrub\version-ranges\src\lib.rs:1219
  21:     0x7ff70ad3b7ac - core::ops::function::impls::impl$0::call<tuple$<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> > >,version_ranges::tests::serde_round_trip::closure_env$1>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\core\src\ops\function.rs:266
  22:     0x7ff70ad20d08 - proptest::test_runner::runner::call_test::closure$4::closure$0<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<version_ranges::tests::serde_round_trip::closure_env$1>,alloc::vec::into_iter::IntoIter<enum2$<core::result::Result
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:258
  23:     0x7ff70ad3658d - core::panic::unwind_safe::impl$25::call_once<enum2$<core::result::Result<tuple$<>,enum2$<proptest::test_runner::errors::TestCaseError> > >,proptest::test_runner::runner::call_test::closure$4::closure_env$0<proptest::sugar::NamedArguments<ref$<str$>,version
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\core\src\panic\unwind_safe.rs:272
  24:     0x7ff70ad43689 - std::panicking::catch_unwind::do_call<core::panic::unwind_safe::AssertUnwindSafe<proptest::test_runner::runner::call_test::closure$4::closure_env$0<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<version_ranges::tests::serde_r
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\std\src\panicking.rs:590
  25:     0x7ff70ad2cd23 - std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<proptest::test_runner::runner::call_test::closure$4::closure_env$0<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<proptest::test_runner::runner::impl$4::run_
  26:     0x7ff70ad2c9fb - std::panicking::catch_unwind
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\std\src\panicking.rs:553
  27:     0x7ff70ad2c9fb - std::panic::catch_unwind<core::panic::unwind_safe::AssertUnwindSafe<proptest::test_runner::runner::call_test::closure$4::closure_env$0<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<version_ranges::tests::serde_round_trip::cl
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\std\src\panic.rs:359
  28:     0x7ff70ad195c4 - proptest::test_runner::runner::call_test::closure$4<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<version_ranges::tests::serde_round_trip::closure_env$1>,alloc::vec::into_iter::IntoIter<enum2$<core::result::Result<tuple$<>,e
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:258
  29:     0x7ff70ac21d5e - proptest::test_runner::scoped_panic_hook::internal::with_hook<enum2$<core::result::Result<enum2$<core::result::Result<tuple$<>,enum2$<proptest::test_runner::errors::TestCaseError> > >,alloc::boxed::Box<dyn$<core::any::Any,core::marker::Send>,alloc::alloc::
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\scoped_panic_hook.rs:130
  30:     0x7ff70ad0d2df - proptest::test_runner::runner::call_test<proptest::sugar::NamedArguments<ref$<str$>,version_ranges::Ranges<u32> >,ref$<version_ranges::tests::serde_round_trip::closure_env$1>,alloc::vec::into_iter::IntoIter<enum2$<core::result::Result<tuple$<>,enum2$<propt
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:256
  31:     0x7ff70acdfb67 - proptest::test_runner::runner::TestRunner::shrink<proptest::strategy::map::Map<proptest::strategy::map::Map<proptest::tuple::TupleValueTree<tuple$<proptest::bool::BoolValueTree,proptest::collection::VecValueTree<proptest::tuple::TupleValueTree<tuple$<propt
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:855
  32:     0x7ff70acbc49a - proptest::test_runner::runner::TestRunner::run_one_with_replay<proptest::strategy::map::Map<proptest::strategy::map::Map<proptest::tuple::TupleValueTree<tuple$<proptest::bool::BoolValueTree,proptest::collection::VecValueTree<proptest::tuple::TupleValueTree
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:742
  33:     0x7ff70aca66dd - proptest::test_runner::runner::TestRunner::gen_and_run_case<proptest::strategy::map::Map<proptest::strategy::map::Map<tuple$<proptest::bool::Any,proptest::collection::VecStrategy<tuple$<proptest::num::u32::Any,proptest::bool::Any> > >,version_ranges::propt
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:670
  34:     0x7ff70acd18cb - proptest::test_runner::runner::TestRunner::run_in_process_with_replay<proptest::strategy::map::Map<proptest::strategy::map::Map<tuple$<proptest::bool::Any,proptest::collection::VecStrategy<tuple$<proptest::num::u32::Any,proptest::bool::Any> > >,version_ran
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:604
  35:     0x7ff70aca2342 - proptest::test_runner::runner::TestRunner::run_in_process<proptest::strategy::map::Map<proptest::strategy::map::Map<tuple$<proptest::bool::Any,proptest::collection::VecStrategy<tuple$<proptest::num::u32::Any,proptest::bool::Any> > >,version_ranges::proptes
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:574
  36:     0x7ff70acde258 - proptest::test_runner::runner::TestRunner::run<proptest::strategy::map::Map<proptest::strategy::map::Map<tuple$<proptest::bool::Any,proptest::collection::VecStrategy<tuple$<proptest::num::u32::Any,proptest::bool::Any> > >,version_ranges::proptest_strategy:
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\test_runner\runner.rs:417
  37:     0x7ff70ac4201b - version_ranges::tests::serde_round_trip
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\sugar.rs:163
  38:     0x7ff70ad37918 - version_ranges::tests::serde_round_trip::closure$0
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\sugar.rs:159
  39:     0x7ff70ac5a7c2 - core::ops::function::FnOnce::call_once<version_ranges::tests::serde_round_trip::closure_env$0,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\core\src\ops\function.rs:253
  40:     0x7ff70adc04e0 - core::ops::function::FnOnce::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\ops\function.rs:253
  41:     0x7ff70adc04e0 - test::__rust_begin_short_backtrace<enum2$<core::result::Result<tuple$<>,alloc::string::String> >,enum2$<core::result::Result<tuple$<>,alloc::string::String> > (*)()>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:663
  42:     0x7ff70addb4f3 - test::run_test_in_process
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:686
  43:     0x7ff70addb4f3 - test::run_test::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:607
  44:     0x7ff70ada981c - test::run_test::closure$1
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:637
  45:     0x7ff70ada981c - std::sys::backtrace::__rust_begin_short_backtrace<test::run_test::closure_env$1,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:158
  46:     0x7ff70adadbdd - core::ops::function::FnOnce::call_once<std::thread::impl$0::spawn_unchecked_::closure_env$1<test::run_test::closure_env$1,tuple$<> >,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\ops\function.rs:253
  47:     0x7ff70ae76bfd - alloc::boxed::impl$29::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1985
  48:     0x7ff70ae76bfd - alloc::boxed::impl$29::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1985
  49:     0x7ff70ae76bfd - std::sys::pal::windows::thread::impl$0::new::thread_start
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\pal\windows\thread.rs:60
  50:     0x7ffe109d259d - BaseThreadInitThunk
  51:     0x7ffe116aaf78 - RtlUserThreadStart

thread 'tests::serde_round_trip' (12732) panicked at version-ranges\src\lib.rs:1211:5:
Test failed: called `Result::unwrap()` on an `Err` value: SpannedError { code: Message("data did not match any variant of untagged enum EitherInterval"), position: Position { line: 1, col: 25 } }.
minimal failing input: range = Ranges {
    segments: [
        (
            Excluded(
                0,
            ),
            Unbounded,
        ),
    ],
}
        successes: 0
        local rejects: 0
        global rejects: 0

stack backtrace:
   0:     0x7ff70ae918d2 - std::backtrace_rs::backtrace::win64::trace
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\..\..\backtrace\src\backtrace\win64.rs:85
   1:     0x7ff70ae918d2 - std::backtrace_rs::backtrace::trace_unsynchronized
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\..\..\backtrace\src\backtrace\mod.rs:66
   2:     0x7ff70ae918d2 - std::sys::backtrace::_print_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:66
   3:     0x7ff70ae918d2 - std::sys::backtrace::impl$0::print::impl$0::fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:39
   4:     0x7ff70ae9bbda - core::fmt::rt::Argument::fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\fmt\rt.rs:173
   5:     0x7ff70ae9bbda - core::fmt::write
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\fmt\mod.rs:1468
   6:     0x7ff70ae6f737 - std::io::default_write_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\io\mod.rs:639
   7:     0x7ff70ae6f737 - std::io::Write::write_fmt<alloc::vec::Vec<u8,alloc::alloc::Global> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\io\mod.rs:1954
   8:     0x7ff70ae7fb75 - std::sys::backtrace::BacktraceLock::print
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:42
   9:     0x7ff70ae843c9 - std::panicking::default_hook::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:301
  10:     0x7ff70ae841f3 - std::panicking::default_hook
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:325
  11:     0x7ff70adc0709 - alloc::boxed::impl$31::call
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1999
  12:     0x7ff70adc0709 - test::test_main_with_exit_callback::closure$0<test::test_main::closure_env$0>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:145
  13:     0x7ff70ae84bca - std::panicking::panic_with_hook
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:842
  14:     0x7ff70ae84a19 - std::panicking::panic_handler::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:707
  15:     0x7ff70ae7fd7f - std::sys::backtrace::__rust_end_short_backtrace<std::panicking::panic_handler::closure_env$0,never$>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:174
  16:     0x7ff70ae6c65e - std::panicking::panic_handler
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\panicking.rs:698
  17:     0x7ff70aeaa2d1 - core::panicking::panic_fmt
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\panicking.rs:75
  18:     0x7ff70ac4212f - version_ranges::tests::serde_round_trip
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\sugar.rs:163
  19:     0x7ff70ad37918 - version_ranges::tests::serde_round_trip::closure$0
                               at C:\Users\me\scoop\persist\rustup\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\proptest-1.6.0\src\sugar.rs:159
  20:     0x7ff70ac5a7c2 - core::ops::function::FnOnce::call_once<version_ranges::tests::serde_round_trip::closure_env$0,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed\library\core\src\ops\function.rs:253
  21:     0x7ff70adc04e0 - core::ops::function::FnOnce::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\ops\function.rs:253
  22:     0x7ff70adc04e0 - test::__rust_begin_short_backtrace<enum2$<core::result::Result<tuple$<>,alloc::string::String> >,enum2$<core::result::Result<tuple$<>,alloc::string::String> > (*)()>
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:663
  23:     0x7ff70addb4f3 - test::run_test_in_process
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:686
  24:     0x7ff70addb4f3 - test::run_test::closure$0
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:607
  25:     0x7ff70ada981c - test::run_test::closure$1
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\test\src\lib.rs:637
  26:     0x7ff70ada981c - std::sys::backtrace::__rust_begin_short_backtrace<test::run_test::closure_env$1,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\backtrace.rs:158
  27:     0x7ff70adadbdd - core::ops::function::FnOnce::call_once<std::thread::impl$0::spawn_unchecked_::closure_env$1<test::run_test::closure_env$1,tuple$<> >,tuple$<> >
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\core\src\ops\function.rs:253
  28:     0x7ff70ae76bfd - alloc::boxed::impl$29::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1985
  29:     0x7ff70ae76bfd - alloc::boxed::impl$29::call_once
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\alloc\src\boxed.rs:1985
  30:     0x7ff70ae76bfd - std::sys::pal::windows::thread::impl$0::new::thread_start
                               at /rustc/54c581243c977c7662c949b5795c31147f8a60ed/library\std\src\sys\pal\windows\thread.rs:60
  31:     0x7ffe109d259d - BaseThreadInitThunk
  32:     0x7ffe116aaf78 - RtlUserThreadStart

[asquared31415]

This is likely this error in ron: ron-rs/ron#579

This probably comes from the following hack which uses type_name to try and detect if a type is equal to a serde private type. The serde type in question is an enum with a lifetime, and lifetimes began to be printed in type_name recently https://github.com/ron-rs/ron/blob/29e244a21cc8eefeceb6a3a7e2be71760a0ce792/src/de/mod.rs#L180-L183

type_name explicitly says that it is for diagnostics use only, and cannot be relied upon. in particular it says:

In addition, the output may change between versions of the compiler.

so I believe this is entirely expected breakage.

Unfortunately it seems ron is blocked on serde not exposing what it needs, so I'm not sure what the best course of action is for that crate.

@rustbot label -needs-triage -C-bug +T-libs-api

cc #145284