[INFO] cloning repository https://github.com/llamicron/lab_grader
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/llamicron/lab_grader" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b6ed054bca8d3f20efc7ed995e23197ee089e6eb
[INFO] testing llamicron/lab_grader against beta-2026-04-21 for beta-1.96-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fllamicron%2Flab_grader" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/llamicron/lab_grader
[INFO] finished tweaking git repo https://github.com/llamicron/lab_grader
[INFO] tweaked toml for git repo https://github.com/llamicron/lab_grader written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/llamicron/lab_grader on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 283 packages to latest compatible versions
[INFO] [stderr]       Adding pretty_assertions v0.6.1 (available: v1.4.1)
[INFO] [stderr]       Adding reqwest v0.10.10 (available: v0.13.2)
[INFO] [stderr]       Adding rocket v0.4.11 (available: v0.5.1)
[INFO] [stderr]       Adding serde_yaml v0.8.26 (available: v0.9.34+deprecated)
[INFO] [stderr]       Adding subtle v2.4.1 (available: v2.6.1)
[INFO] [stderr]       Adding wasi v0.10.0+wasi-snapshot-preview1 (available: v0.10.2+wasi-snapshot-preview1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fc10f26d2d62485b2118bcbd37e05a2db2445740faa767ebf96ba44ab75ad9da
[INFO] running `Command { std: "docker" "start" "-a" "fc10f26d2d62485b2118bcbd37e05a2db2445740faa767ebf96ba44ab75ad9da", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fc10f26d2d62485b2118bcbd37e05a2db2445740faa767ebf96ba44ab75ad9da", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc10f26d2d62485b2118bcbd37e05a2db2445740faa767ebf96ba44ab75ad9da", kill_on_drop: false }`
[INFO] [stdout] fc10f26d2d62485b2118bcbd37e05a2db2445740faa767ebf96ba44ab75ad9da
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 16334cc09d6c8ae6667d8a7b5548ff7ed20788d97e3ed505d4e3933ebe10ecfd
[INFO] running `Command { std: "docker" "start" "-a" "16334cc09d6c8ae6667d8a7b5548ff7ed20788d97e3ed505d4e3933ebe10ecfd", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.106
[INFO] [stderr]    Compiling unicode-ident v1.0.24
[INFO] [stderr]    Compiling quote v1.0.45
[INFO] [stderr]    Compiling libc v0.2.186
[INFO] [stderr]    Compiling typenum v1.20.0
[INFO] [stderr]    Compiling log v0.4.29
[INFO] [stderr]    Compiling generic-array v0.14.9
[INFO] [stderr]    Compiling memchr v2.8.0
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling subtle v2.4.1
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling slab v0.4.12
[INFO] [stderr]    Compiling yansi v0.5.1
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling find-msvc-tools v0.1.9
[INFO] [stderr]    Compiling serde_core v1.0.228
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling opaque-debug v0.3.1
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling cc v1.2.61
[INFO] [stderr]    Compiling zerocopy v0.8.48
[INFO] [stderr]    Compiling once_cell v1.21.4
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling pkg-config v0.3.33
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling cipher v0.2.5
[INFO] [stderr]    Compiling futures-core v0.3.32
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling itoa v1.0.18
[INFO] [stderr]    Compiling smallvec v1.15.1
[INFO] [stderr]    Compiling tinyvec v1.11.0
[INFO] [stderr]    Compiling digest v0.9.0
[INFO] [stderr]    Compiling num_cpus v1.17.0
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.39
[INFO] [stderr]    Compiling getrandom v0.2.17
[INFO] [stderr]    Compiling universal-hash v0.4.1
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling openssl-sys v0.9.114
[INFO] [stderr]    Compiling bytes v0.5.6
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling litemap v0.8.2
[INFO] [stderr]    Compiling cpuid-bool v0.2.0
[INFO] [stderr]    Compiling writeable v0.6.3
[INFO] [stderr]    Compiling polyval v0.4.5
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling unicode-normalization v0.1.25
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling aes-soft v0.6.4
[INFO] [stderr]    Compiling crypto-mac v0.10.1
[INFO] [stderr]    Compiling pear_codegen v0.1.5
[INFO] [stderr]    Compiling pin-project-lite v0.2.17
[INFO] [stderr]    Compiling icu_normalizer_data v2.2.0
[INFO] [stderr]    Compiling lazy_static v1.5.0
[INFO] [stderr]    Compiling icu_properties_data v2.2.0
[INFO] [stderr]    Compiling pin-project-lite v0.1.12
[INFO] [stderr]    Compiling matches v0.1.10
[INFO] [stderr]    Compiling tokio v0.2.25
[INFO] [stderr]    Compiling hmac v0.10.1
[INFO] [stderr] error: failed to run custom build command for `pear_codegen v0.1.5`
[INFO] [stderr] note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/pear_codegen-70a1200799c39ee7/build-script-build` (exit status: 101)
[INFO] [stderr]   --- stderr
[INFO] [stderr]   Error: Pear requires a 'dev' or 'nightly' version of rustc.
[INFO] [stderr]   Installed version: 1.96.0 (2026-04-20)
[INFO] [stderr]   Minimum required:  1.31.0-nightly (2018-10-05)
[INFO] [stderr] 
[INFO] [stderr]   thread 'main' (833) panicked at /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/pear_codegen-0.1.5/build.rs:24:13:
[INFO] [stderr]   Aborting compilation due to incompatible compiler.
[INFO] [stderr]   stack backtrace:
[INFO] [stderr]      0:     0x6053c7c0b1ca - std[128c3efe2914e152]::backtrace_rs::backtrace::libunwind::trace
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stderr]      1:     0x6053c7c0b1ca - std[128c3efe2914e152]::backtrace_rs::backtrace::trace_unsynchronized::<std[128c3efe2914e152]::sys::backtrace::_print_fmt::{closure#1}>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stderr]      2:     0x6053c7c0b1ca - std[128c3efe2914e152]::sys::backtrace::_print_fmt
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/sys/backtrace.rs:74:9
[INFO] [stderr]      3:     0x6053c7c0b1ca - <<std[128c3efe2914e152]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[6771d259883166e6]::fmt::Display>::fmt
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/sys/backtrace.rs:44:26
[INFO] [stderr]      4:     0x6053c7c1c96a - <core[6771d259883166e6]::fmt::rt::Argument>::fmt
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/core/src/fmt/rt.rs:152:76
[INFO] [stderr]      5:     0x6053c7c1c96a - core[6771d259883166e6]::fmt::write
[INFO] [stderr]      6:     0x6053c7c0f792 - std[128c3efe2914e152]::io::default_write_fmt::<std[128c3efe2914e152]::sys::stdio::unix::Stderr>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/io/mod.rs:621:11
[INFO] [stderr]      7:     0x6053c7c0f792 - <std[128c3efe2914e152]::sys::stdio::unix::Stderr as std[128c3efe2914e152]::io::Write>::write_fmt
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/io/mod.rs:1976:13
[INFO] [stderr]      8:     0x6053c7bf0c8f - <std[128c3efe2914e152]::sys::backtrace::BacktraceLock>::print
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/sys/backtrace.rs:47:9
[INFO] [stderr]      9:     0x6053c7bf0c8f - std[128c3efe2914e152]::panicking::default_hook::{closure#0}
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:292:27
[INFO] [stderr]     10:     0x6053c7c06d71 - std[128c3efe2914e152]::panicking::default_hook
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:319:9
[INFO] [stderr]     11:     0x6053c7c06f2b - std[128c3efe2914e152]::panicking::panic_with_hook
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:825:13
[INFO] [stderr]     12:     0x6053c7bf02ac - std[128c3efe2914e152]::panicking::begin_panic::<&str>::{closure#0}
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:762:9
[INFO] [stderr]     13:     0x6053c7be6069 - std[128c3efe2914e152]::sys::backtrace::__rust_end_short_backtrace::<std[128c3efe2914e152]::panicking::begin_panic<&str>::{closure#0}, !>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/sys/backtrace.rs:182:18
[INFO] [stderr]     14:     0x6053c7be3910 - std[128c3efe2914e152]::panicking::begin_panic::<&str>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:761:5
[INFO] [stderr]     15:     0x6053c7bc7f7a - build_script_build::main::h7434993596a64b9b
[INFO] [stderr]     16:     0x6053c7bc8663 - core::ops::function::FnOnce::call_once::h88c3e11451b5fe44
[INFO] [stderr]     17:     0x6053c7bc83c6 - std::sys::backtrace::__rust_begin_short_backtrace::h3c86e88b6513b064
[INFO] [stderr]     18:     0x6053c7bc83a9 - std::rt::lang_start::{{closure}}::h263ee8016fbf76b3
[INFO] [stderr]     19:     0x6053c7c05fb4 - <&dyn core[6771d259883166e6]::ops::function::Fn<(), Output = i32> + core[6771d259883166e6]::marker::Sync + core[6771d259883166e6]::panic::unwind_safe::RefUnwindSafe as core[6771d259883166e6]::ops::function::FnOnce<()>>::call_once
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/core/src/ops/function.rs:287:21
[INFO] [stderr]     20:     0x6053c7c05fb4 - std[128c3efe2914e152]::panicking::catch_unwind::do_call::<&dyn core[6771d259883166e6]::ops::function::Fn<(), Output = i32> + core[6771d259883166e6]::marker::Sync + core[6771d259883166e6]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:581:40
[INFO] [stderr]     21:     0x6053c7c05fb4 - std[128c3efe2914e152]::panicking::catch_unwind::<i32, &dyn core[6771d259883166e6]::ops::function::Fn<(), Output = i32> + core[6771d259883166e6]::marker::Sync + core[6771d259883166e6]::panic::unwind_safe::RefUnwindSafe>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:544:19
[INFO] [stderr]     22:     0x6053c7c05fb4 - std[128c3efe2914e152]::panic::catch_unwind::<&dyn core[6771d259883166e6]::ops::function::Fn<(), Output = i32> + core[6771d259883166e6]::marker::Sync + core[6771d259883166e6]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panic.rs:359:14
[INFO] [stderr]     23:     0x6053c7c05fb4 - std[128c3efe2914e152]::rt::lang_start_internal::{closure#0}
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/rt.rs:175:24
[INFO] [stderr]     24:     0x6053c7c05fb4 - std[128c3efe2914e152]::panicking::catch_unwind::do_call::<std[128c3efe2914e152]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:581:40
[INFO] [stderr]     25:     0x6053c7c05fb4 - std[128c3efe2914e152]::panicking::catch_unwind::<isize, std[128c3efe2914e152]::rt::lang_start_internal::{closure#0}>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panicking.rs:544:19
[INFO] [stderr]     26:     0x6053c7c05fb4 - std[128c3efe2914e152]::panic::catch_unwind::<std[128c3efe2914e152]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/panic.rs:359:14
[INFO] [stderr]     27:     0x6053c7c05fb4 - std[128c3efe2914e152]::rt::lang_start_internal
[INFO] [stderr]                                  at /rustc/8489f1adbe1c8f8921cf18b9962cf565237a5489/library/std/src/rt.rs:171:5
[INFO] [stderr]     28:     0x6053c7bc8391 - std::rt::lang_start::hf05299a6131f971e
[INFO] [stderr]     29:     0x6053c7bcb045 - main
[INFO] [stderr]     30:     0x787d2bcc51ca - <unknown>
[INFO] [stderr]     31:     0x787d2bcc528b - __libc_start_main
[INFO] [stderr]     32:     0x6053c7bc7825 - _start
[INFO] [stderr]     33:                0x0 - <unknown>
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "16334cc09d6c8ae6667d8a7b5548ff7ed20788d97e3ed505d4e3933ebe10ecfd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "16334cc09d6c8ae6667d8a7b5548ff7ed20788d97e3ed505d4e3933ebe10ecfd", kill_on_drop: false }`
[INFO] [stdout] 16334cc09d6c8ae6667d8a7b5548ff7ed20788d97e3ed505d4e3933ebe10ecfd
