[INFO] cloning repository https://github.com/ac999/round_robin_loadbalancer
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ac999/round_robin_loadbalancer" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fac999%2Fround_robin_loadbalancer", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fac999%2Fround_robin_loadbalancer'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1d8f5e98321031b090052f0597fda4a8a641fafb
[INFO] checking ac999/round_robin_loadbalancer against try#8ea250bdb76176ecb0225baa34aa634b024ae0e2 for pr-101692
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fac999%2Fround_robin_loadbalancer" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ac999/round_robin_loadbalancer on toolchain 8ea250bdb76176ecb0225baa34aa634b024ae0e2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ea250bdb76176ecb0225baa34aa634b024ae0e2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ac999/round_robin_loadbalancer
[INFO] finished tweaking git repo https://github.com/ac999/round_robin_loadbalancer
[INFO] tweaked toml for git repo https://github.com/ac999/round_robin_loadbalancer written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/ac999/round_robin_loadbalancer already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ea250bdb76176ecb0225baa34aa634b024ae0e2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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@sha256:824c28ce115f6b999260af6986f3384c158e782489540e41c0b698ca1d9fd927" "/opt/rustwide/cargo-home/bin/cargo" "+8ea250bdb76176ecb0225baa34aa634b024ae0e2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a670701a1911fc5a12ee0fe65ac26b8d77caa8d522d5bcea95d42a9b6ffd911
[INFO] running `Command { std: "docker" "start" "-a" "1a670701a1911fc5a12ee0fe65ac26b8d77caa8d522d5bcea95d42a9b6ffd911", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a670701a1911fc5a12ee0fe65ac26b8d77caa8d522d5bcea95d42a9b6ffd911", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a670701a1911fc5a12ee0fe65ac26b8d77caa8d522d5bcea95d42a9b6ffd911", kill_on_drop: false }`
[INFO] [stdout] 1a670701a1911fc5a12ee0fe65ac26b8d77caa8d522d5bcea95d42a9b6ffd911
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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@sha256:824c28ce115f6b999260af6986f3384c158e782489540e41c0b698ca1d9fd927" "/opt/rustwide/cargo-home/bin/cargo" "+8ea250bdb76176ecb0225baa34aa634b024ae0e2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] def68f6aaea069369702ebf0424e839a1d5ae08a6ad1a86b3198e01d2bb86e4c
[INFO] running `Command { std: "docker" "start" "-a" "def68f6aaea069369702ebf0424e839a1d5ae08a6ad1a86b3198e01d2bb86e4c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.99
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling futures-core v0.3.16
[INFO] [stderr]    Compiling futures-task v0.3.16
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling futures-channel v0.3.16
[INFO] [stderr]    Compiling serde_derive v1.0.127
[INFO] [stderr]     Checking pin-project-lite v0.2.7
[INFO] [stderr]     Checking futures-sink v0.3.16
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking slab v0.4.4
[INFO] [stderr]     Checking futures-io v0.3.16
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]    Compiling cc v1.0.69
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]     Checking pin-utils v0.1.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]     Checking once_cell v1.8.0
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking bitflags v1.3.1
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr] error: failed to run custom build command for `libc v0.2.99`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/libc-b75b3f91b00f7a16/build-script-build` (exit status: 101)
[INFO] [stderr]   --- stdout
[INFO] [stderr]   cargo:rerun-if-changed=build.rs
[INFO] [stderr] 
[INFO] [stderr]   --- stderr
[INFO] [stderr]   thread 'main' panicked at 'Failed to get rustc version', /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/libc-0.2.99/build.rs:9:63
[INFO] [stderr]   stack backtrace:
[INFO] [stderr]      0:     0x55bf0f420460 - std::backtrace_rs::backtrace::libunwind::trace::h07f6f3f62143c2f1
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
[INFO] [stderr]      1:     0x55bf0f420460 - std::backtrace_rs::backtrace::trace_unsynchronized::ha4af296646eff8ca
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
[INFO] [stderr]      2:     0x55bf0f420460 - std::sys_common::backtrace::_print_fmt::h6c078bd86d05ddda
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:66:5
[INFO] [stderr]      3:     0x55bf0f420460 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hee15a79371583970
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:45:22
[INFO] [stderr]      4:     0x55bf0f43d7fe - core::fmt::write::hf2e27bdaba79f677
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/fmt/mod.rs:1202:17
[INFO] [stderr]      5:     0x55bf0f41d7e5 - std::io::Write::write_fmt::ha1817aee185c081a
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/io/mod.rs:1679:15
[INFO] [stderr]      6:     0x55bf0f421ae3 - std::sys_common::backtrace::_print::hf9a456aef6ad95d2
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:48:5
[INFO] [stderr]      7:     0x55bf0f421ae3 - std::sys_common::backtrace::print::h2da0b4b6a2c7b2ed
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:35:9
[INFO] [stderr]      8:     0x55bf0f421ae3 - std::panicking::default_hook::{{closure}}::he4468ced72b6d9a8
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:295:22
[INFO] [stderr]      9:     0x55bf0f4217cf - std::panicking::default_hook::h1bb5aeb06711134e
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:314:9
[INFO] [stderr]     10:     0x55bf0f42218a - std::panicking::rust_panic_with_hook::haa10863c66cdd6aa
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:698:17
[INFO] [stderr]     11:     0x55bf0f422087 - std::panicking::begin_panic_handler::{{closure}}::h4b82d065222c5bc4
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:588:13
[INFO] [stderr]     12:     0x55bf0f42090c - std::sys_common::backtrace::__rust_end_short_backtrace::hac689cdb68db7f01
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:138:18
[INFO] [stderr]     13:     0x55bf0f421da2 - rust_begin_unwind
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:584:5
[INFO] [stderr]     14:     0x55bf0f3f9a93 - core::panicking::panic_fmt::hbc8818ca15fe0c9e
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/panicking.rs:142:14
[INFO] [stderr]     15:     0x55bf0f43caa1 - core::panicking::panic_display::hc0b8dcf31558688c
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/panicking.rs:72:5
[INFO] [stderr]     16:     0x55bf0f43ca4b - core::panicking::panic_str::h0dadaa21d68a2aa6
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/panicking.rs:56:5
[INFO] [stderr]     17:     0x55bf0f3f9906 - core::option::expect_failed::h9e66908e6cc17b58
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/option.rs:1880:5
[INFO] [stderr]     18:     0x55bf0f3fba22 - core::option::Option<T>::expect::he2474a52e09a4e85
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/option.rs:738:21
[INFO] [stderr]     19:     0x55bf0f400614 - build_script_build::main::h0a75ceedd4b7c574
[INFO] [stderr]                                  at /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/libc-0.2.99/build.rs:9:41
[INFO] [stderr]     20:     0x55bf0f40371b - core::ops::function::FnOnce::call_once::hd55573bf18705185
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/ops/function.rs:248:5
[INFO] [stderr]     21:     0x55bf0f40364e - std::sys_common::backtrace::__rust_begin_short_backtrace::h46328f5635844a6a
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/sys_common/backtrace.rs:122:18
[INFO] [stderr]     22:     0x55bf0f3fcfa1 - std::rt::lang_start::{{closure}}::h9cbaf8ba211d52b6
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/rt.rs:166:18
[INFO] [stderr]     23:     0x55bf0f41ae1f - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::hc214aeaf2bdd199e
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/core/src/ops/function.rs:280:13
[INFO] [stderr]     24:     0x55bf0f41ae1f - std::panicking::try::do_call::hcff8a9964c5a8ed9
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:492:40
[INFO] [stderr]     25:     0x55bf0f41ae1f - std::panicking::try::h43dbacefe2436fcd
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:456:19
[INFO] [stderr]     26:     0x55bf0f41ae1f - std::panic::catch_unwind::h44cc723b3d02a7c5
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panic.rs:137:14
[INFO] [stderr]     27:     0x55bf0f41ae1f - std::rt::lang_start_internal::{{closure}}::h248747dd5aea9860
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/rt.rs:148:48
[INFO] [stderr]     28:     0x55bf0f41ae1f - std::panicking::try::do_call::h4646f69ac0b58d7d
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:492:40
[INFO] [stderr]     29:     0x55bf0f41ae1f - std::panicking::try::h029dda102f1c6d71
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panicking.rs:456:19
[INFO] [stderr]     30:     0x55bf0f41ae1f - std::panic::catch_unwind::h0def18963bdd482a
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/panic.rs:137:14
[INFO] [stderr]     31:     0x55bf0f41ae1f - std::rt::lang_start_internal::h7bcbe5e0d7f0056f
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/rt.rs:148:20
[INFO] [stderr]     32:     0x55bf0f3fcf7a - std::rt::lang_start::hc0aae67d462ee78f
[INFO] [stderr]                                  at /rustc/8ea250bdb76176ecb0225baa34aa634b024ae0e2/library/std/src/rt.rs:165:17
[INFO] [stderr]     33:     0x55bf0f401af1 - main
[INFO] [stderr]     34:     0x7f393a8cd083 - __libc_start_main
[INFO] [stderr]     35:     0x55bf0f3f9c6e - _start
[INFO] [stderr]     36:                0x0 - <unknown>
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "def68f6aaea069369702ebf0424e839a1d5ae08a6ad1a86b3198e01d2bb86e4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "def68f6aaea069369702ebf0424e839a1d5ae08a6ad1a86b3198e01d2bb86e4c", kill_on_drop: false }`
[INFO] [stdout] def68f6aaea069369702ebf0424e839a1d5ae08a6ad1a86b3198e01d2bb86e4c