[INFO] cloning repository https://github.com/alexclear/rust-koans-answers
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/alexclear/rust-koans-answers" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexclear%2Frust-koans-answers", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexclear%2Frust-koans-answers'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 89e124c056c315e10c6d5ab8548902c0cfc64be5
[INFO] checking alexclear/rust-koans-answers against beta-2020-07-24 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexclear%2Frust-koans-answers" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alexclear/rust-koans-answers on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/alexclear/rust-koans-answers
[INFO] finished tweaking git repo https://github.com/alexclear/rust-koans-answers
[INFO] tweaked toml for git repo https://github.com/alexclear/rust-koans-answers written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/alexclear/rust-koans-answers already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f6650a92e2a5fae8b5b2008aed7ea8ee9a088fa5637841f0c9b07f9c6955bbe5
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f6650a92e2a5fae8b5b2008aed7ea8ee9a088fa5637841f0c9b07f9c6955bbe5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f6650a92e2a5fae8b5b2008aed7ea8ee9a088fa5637841f0c9b07f9c6955bbe5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f6650a92e2a5fae8b5b2008aed7ea8ee9a088fa5637841f0c9b07f9c6955bbe5", kill_on_drop: false }`
[INFO] [stdout] f6650a92e2a5fae8b5b2008aed7ea8ee9a088fa5637841f0c9b07f9c6955bbe5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 2ffea22626eb3276cf2b33248398b0e6d639702650a9211aae74c25bfa2342c1
[INFO] running `Command { std: "docker" "start" "-a" "2ffea22626eb3276cf2b33248398b0e6d639702650a9211aae74c25bfa2342c1", kill_on_drop: false }`
[INFO] [stderr]    Compiling koans v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: failed to run custom build command for `koans v0.2.0 (/opt/rustwide/workdir)`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/koans-2ec001cfc51a302e/build-script-build` (exit code: 101)
[INFO] [stderr]   --- stderr
[INFO] [stderr]   thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 30, kind: Other, message: "Read-only file system" }', build.rs:7:10
[INFO] [stderr]   stack backtrace:
[INFO] [stderr]      0:     0x55e160754055 - backtrace::backtrace::libunwind::trace::h5e2646fa3eddf2ea
[INFO] [stderr]                                  at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
[INFO] [stderr]      1:     0x55e160754055 - backtrace::backtrace::trace_unsynchronized::hb95dd7f77ce47877
[INFO] [stderr]                                  at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
[INFO] [stderr]      2:     0x55e160754055 - std::sys_common::backtrace::_print_fmt::h5e71b67af43fd70d
[INFO] [stderr]                                  at src/libstd/sys_common/backtrace.rs:78
[INFO] [stderr]      3:     0x55e160754055 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hdb4a83d2b61107e5
[INFO] [stderr]                                  at src/libstd/sys_common/backtrace.rs:59
[INFO] [stderr]      4:     0x55e16077119c - core::fmt::write::ha20e7262fa3e8a7a
[INFO] [stderr]                                  at src/libcore/fmt/mod.rs:1076
[INFO] [stderr]      5:     0x55e160752722 - std::io::Write::write_fmt::h1aebfe8a5a79e36d
[INFO] [stderr]                                  at src/libstd/io/mod.rs:1537
[INFO] [stderr]      6:     0x55e160756410 - std::sys_common::backtrace::_print::h9c07314cc66ba539
[INFO] [stderr]                                  at src/libstd/sys_common/backtrace.rs:62
[INFO] [stderr]      7:     0x55e160756410 - std::sys_common::backtrace::print::hd1fd65f49a2d8544
[INFO] [stderr]                                  at src/libstd/sys_common/backtrace.rs:49
[INFO] [stderr]      8:     0x55e160756410 - std::panicking::default_hook::{{closure}}::h222da46485ab36fc
[INFO] [stderr]                                  at src/libstd/panicking.rs:198
[INFO] [stderr]      9:     0x55e16075615c - std::panicking::default_hook::hc5868949d129ed00
[INFO] [stderr]                                  at src/libstd/panicking.rs:217
[INFO] [stderr]     10:     0x55e160756a53 - std::panicking::rust_panic_with_hook::h26a6ab8b0993c0c8
[INFO] [stderr]                                  at src/libstd/panicking.rs:526
[INFO] [stderr]     11:     0x55e16075664b - rust_begin_unwind
[INFO] [stderr]                                  at src/libstd/panicking.rs:437
[INFO] [stderr]     12:     0x55e1607705a1 - core::panicking::panic_fmt::h17139c2000299725
[INFO] [stderr]                                  at src/libcore/panicking.rs:85
[INFO] [stderr]     13:     0x55e1607703c3 - core::option::expect_none_failed::h972f96abb4ec8952
[INFO] [stderr]                                  at src/libcore/option.rs:1269
[INFO] [stderr]     14:     0x55e16074ec7b - core::result::Result<T,E>::unwrap::h8ef404be8ff708da
[INFO] [stderr]                                  at /rustc/6f959902b3103c49ca981fbc01871589c3498489/src/libcore/result.rs:1005
[INFO] [stderr]     15:     0x55e16074ebdb - build_script_build::main::h4ff450b1171008b7
[INFO] [stderr]                                  at /opt/rustwide/workdir/build.rs:4
[INFO] [stderr]     16:     0x55e16074e8bb - std::rt::lang_start::{{closure}}::h6a7b7f0dc44fa660
[INFO] [stderr]                                  at /rustc/6f959902b3103c49ca981fbc01871589c3498489/src/libstd/rt.rs:67
[INFO] [stderr]     17:     0x55e160756e23 - std::rt::lang_start_internal::{{closure}}::h84a998219831fa70
[INFO] [stderr]                                  at src/libstd/rt.rs:52
[INFO] [stderr]     18:     0x55e160756e23 - std::panicking::try::do_call::he8e1d689a3e26def
[INFO] [stderr]                                  at src/libstd/panicking.rs:348
[INFO] [stderr]     19:     0x55e160756e23 - std::panicking::try::h264b6eebc2fa7bbf
[INFO] [stderr]                                  at src/libstd/panicking.rs:325
[INFO] [stderr]     20:     0x55e160756e23 - std::panic::catch_unwind::hbf28fafa723b2128
[INFO] [stderr]                                  at src/libstd/panic.rs:394
[INFO] [stderr]     21:     0x55e160756e23 - std::rt::lang_start_internal::he959aa59bc3ec202
[INFO] [stderr]                                  at src/libstd/rt.rs:51
[INFO] [stderr]     22:     0x55e16074e897 - std::rt::lang_start::h2208daa7e9cbf8da
[INFO] [stderr]                                  at /rustc/6f959902b3103c49ca981fbc01871589c3498489/src/libstd/rt.rs:67
[INFO] [stderr]     23:     0x55e16074ec1a - main
[INFO] [stderr]     24:     0x7f5e19b410b3 - __libc_start_main
[INFO] [stderr]     25:     0x55e16074e17e - _start
[INFO] [stderr]     26:                0x0 - <unknown>
[INFO] running `Command { std: "docker" "inspect" "2ffea22626eb3276cf2b33248398b0e6d639702650a9211aae74c25bfa2342c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2ffea22626eb3276cf2b33248398b0e6d639702650a9211aae74c25bfa2342c1", kill_on_drop: false }`
[INFO] [stdout] 2ffea22626eb3276cf2b33248398b0e6d639702650a9211aae74c25bfa2342c1
