[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] documenting alexclear/rust-koans-answers against nightly for scrape-examples
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Falexclear%2Frust-koans-answers" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/alexclear/rust-koans-answers on toolchain nightly
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+nightly" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", 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-3/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" "+nightly" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:bb5b0feb4f87116a4ea905b7ff5bf5b85913db05e9f0fbc1abdd3168928d9075" "/opt/rustwide/cargo-home/bin/cargo" "+nightly" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f8c743f4b97741ba318fae239aa621813887cf58013244e474a62b844afa1d7f
[INFO] running `Command { std: "docker" "start" "-a" "f8c743f4b97741ba318fae239aa621813887cf58013244e474a62b844afa1d7f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f8c743f4b97741ba318fae239aa621813887cf58013244e474a62b844afa1d7f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f8c743f4b97741ba318fae239aa621813887cf58013244e474a62b844afa1d7f", kill_on_drop: false }`
[INFO] [stdout] f8c743f4b97741ba318fae239aa621813887cf58013244e474a62b844afa1d7f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:bb5b0feb4f87116a4ea905b7ff5bf5b85913db05e9f0fbc1abdd3168928d9075" "/opt/rustwide/cargo-home/bin/cargo" "+nightly" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d26085ca74968648ce9ccd91ad0ef736299bcef40890be8a8228da3dd31b21d
[INFO] running `Command { std: "docker" "start" "-a" "8d26085ca74968648ce9ccd91ad0ef736299bcef40890be8a8228da3dd31b21d", 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-fe0eb64126fd436a/build-script-build` (exit status: 101)
[INFO] [stderr]   --- stderr
[INFO] [stderr]   thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 30, kind: ReadOnlyFilesystem, message: "Read-only file system" }', build.rs:7:10
[INFO] [stderr]   stack backtrace:
[INFO] [stderr]      0:     0x5564555dc5ba - std::backtrace_rs::backtrace::libunwind::trace::h3bfe63c4aecfa0e2
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
[INFO] [stderr]      1:     0x5564555dc5ba - std::backtrace_rs::backtrace::trace_unsynchronized::h978c02637c6cb8f9
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
[INFO] [stderr]      2:     0x5564555dc5ba - std::sys_common::backtrace::_print_fmt::h86a708dcb1665377
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:65:5
[INFO] [stderr]      3:     0x5564555dc5ba - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hdbf89765373fb801
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:44:22
[INFO] [stderr]      4:     0x5564555f66ee - core::fmt::write::hbf11a3bb4e6d2aba
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/fmt/mod.rs:1208:17
[INFO] [stderr]      5:     0x5564555da745 - std::io::Write::write_fmt::hd68261eacc348bbd
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/io/mod.rs:1682:15
[INFO] [stderr]      6:     0x5564555dc385 - std::sys_common::backtrace::_print::ha8e375b58cdeca4a
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:47:5
[INFO] [stderr]      7:     0x5564555dc385 - std::sys_common::backtrace::print::he3086c07df1167ca
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:34:9
[INFO] [stderr]      8:     0x5564555dda0f - std::panicking::default_hook::{{closure}}::h0c12a9095c948e43
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:267:22
[INFO] [stderr]      9:     0x5564555dd74b - std::panicking::default_hook::h1ae5478ad617eb24
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:286:9
[INFO] [stderr]     10:     0x5564555de11c - std::panicking::rust_panic_with_hook::h63a24f957ccb5d93
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:688:13
[INFO] [stderr]     11:     0x5564555ddeb9 - std::panicking::begin_panic_handler::{{closure}}::h1499194b322f3b28
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:579:13
[INFO] [stderr]     12:     0x5564555dca6c - std::sys_common::backtrace::__rust_end_short_backtrace::h5569dab7b5c29ca8
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:137:18
[INFO] [stderr]     13:     0x5564555ddbc2 - rust_begin_unwind
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:575:5
[INFO] [stderr]     14:     0x5564555c3d93 - core::panicking::panic_fmt::h81b99a9e904184d4
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/panicking.rs:64:14
[INFO] [stderr]     15:     0x5564555c4163 - core::result::unwrap_failed::h524cd100bfaa4af3
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/result.rs:1791:5
[INFO] [stderr]     16:     0x5564555c538b - core::result::Result<T,E>::unwrap::h614189ac0948ec97
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/result.rs:1113:23
[INFO] [stderr]     17:     0x5564555c4c07 - build_script_build::main::h9f8621118eb67725
[INFO] [stderr]                                  at /opt/rustwide/workdir/build.rs:4:5
[INFO] [stderr]     18:     0x5564555c50eb - core::ops::function::FnOnce::call_once::h271b74c79e8b00d7
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/ops/function.rs:507:5
[INFO] [stderr]     19:     0x5564555c437e - std::sys_common::backtrace::__rust_begin_short_backtrace::h65ea2b4b48ff0433
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/sys_common/backtrace.rs:121:18
[INFO] [stderr]     20:     0x5564555c4b41 - std::rt::lang_start::{{closure}}::h28f2db5ac8796549
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/rt.rs:166:18
[INFO] [stderr]     21:     0x5564555d85ec - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::h78c42ac725efa1cf
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/core/src/ops/function.rs:606:13
[INFO] [stderr]     22:     0x5564555d85ec - std::panicking::try::do_call::he9c2e2d3c1d542c9
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:483:40
[INFO] [stderr]     23:     0x5564555d85ec - std::panicking::try::h1c6aa5d0fbd926ce
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:447:19
[INFO] [stderr]     24:     0x5564555d85ec - std::panic::catch_unwind::h8c18c387443a8343
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panic.rs:137:14
[INFO] [stderr]     25:     0x5564555d85ec - std::rt::lang_start_internal::{{closure}}::h121da69a0c637bbc
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/rt.rs:148:48
[INFO] [stderr]     26:     0x5564555d85ec - std::panicking::try::do_call::h02c50a2227007615
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:483:40
[INFO] [stderr]     27:     0x5564555d85ec - std::panicking::try::h2e22346eb385c3b2
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panicking.rs:447:19
[INFO] [stderr]     28:     0x5564555d85ec - std::panic::catch_unwind::hba27888842669aa2
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/panic.rs:137:14
[INFO] [stderr]     29:     0x5564555d85ec - std::rt::lang_start_internal::hfeb0a6ef3b443c94
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/rt.rs:148:20
[INFO] [stderr]     30:     0x5564555c4b1a - std::rt::lang_start::h3125c3b516886f85
[INFO] [stderr]                                  at /rustc/bdb07a8ec8e77aa10fb84fae1d4ff71c21180bb4/library/std/src/rt.rs:165:17
[INFO] [stderr]     31:     0x5564555c4c3e - main
[INFO] [stderr]     32:     0x7f74c6e19083 - __libc_start_main
[INFO] [stderr]     33:     0x5564555c42ae - _start
[INFO] [stderr]     34:                0x0 - <unknown>
[INFO] running `Command { std: "docker" "inspect" "8d26085ca74968648ce9ccd91ad0ef736299bcef40890be8a8228da3dd31b21d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d26085ca74968648ce9ccd91ad0ef736299bcef40890be8a8228da3dd31b21d", kill_on_drop: false }`
[INFO] [stdout] 8d26085ca74968648ce9ccd91ad0ef736299bcef40890be8a8228da3dd31b21d