[INFO] updating cached repository j3h/rust-koans
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/j3h/rust-koans
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/j3h/rust-koans" "work/ex/pr-63247/sources/master#452087b4bf18cece2d52d7cd8c9147195e5404bf/gh/j3h/rust-koans"`
[INFO] [stderr] Cloning into 'work/ex/pr-63247/sources/master#452087b4bf18cece2d52d7cd8c9147195e5404bf/gh/j3h/rust-koans'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/j3h/rust-koans" "work/ex/pr-63247/sources/try#757dacae0a9f1b46b3ab58a1f1232332e8fc7dab/gh/j3h/rust-koans"`
[INFO] [stderr] Cloning into 'work/ex/pr-63247/sources/try#757dacae0a9f1b46b3ab58a1f1232332e8fc7dab/gh/j3h/rust-koans'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] cc29866cd11b1e11dd61018baddd0f75fe6c3310
[INFO] sha for GitHub repo j3h/rust-koans: cc29866cd11b1e11dd61018baddd0f75fe6c3310
[INFO] validating manifest of j3h/rust-koans on toolchain master#452087b4bf18cece2d52d7cd8c9147195e5404bf
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+452087b4bf18cece2d52d7cd8c9147195e5404bf-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of j3h/rust-koans on toolchain try#757dacae0a9f1b46b3ab58a1f1232332e8fc7dab
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+757dacae0a9f1b46b3ab58a1f1232332e8fc7dab-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing j3h/rust-koans
[INFO] finished frobbing j3h/rust-koans
[INFO] frobbed toml for j3h/rust-koans written to work/ex/pr-63247/sources/master#452087b4bf18cece2d52d7cd8c9147195e5404bf/gh/j3h/rust-koans/Cargo.toml
[INFO] started frobbing j3h/rust-koans
[INFO] finished frobbing j3h/rust-koans
[INFO] frobbed toml for j3h/rust-koans written to work/ex/pr-63247/sources/try#757dacae0a9f1b46b3ab58a1f1232332e8fc7dab/gh/j3h/rust-koans/Cargo.toml
[INFO] crate j3h/rust-koans already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+452087b4bf18cece2d52d7cd8c9147195e5404bf-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+757dacae0a9f1b46b3ab58a1f1232332e8fc7dab-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking j3h/rust-koans against master#452087b4bf18cece2d52d7cd8c9147195e5404bf for pr-63247
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63247/worker-4/master#452087b4bf18cece2d52d7cd8c9147195e5404bf:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63247/sources/master#452087b4bf18cece2d52d7cd8c9147195e5404bf/gh/j3h/rust-koans:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+452087b4bf18cece2d52d7cd8c9147195e5404bf-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] e73d443134ca943d5b0a1f6da56e61f129653f5c1c45cf003c3736c9c7574ebd
[INFO] running `"docker" "start" "-a" "e73d443134ca943d5b0a1f6da56e61f129653f5c1c45cf003c3736c9c7574ebd"`
[INFO] [stderr]    Compiling koans v0.2.2 (/opt/crater/workdir)
[INFO] [stderr] error: failed to run custom build command for `koans v0.2.2 (/opt/crater/workdir)`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/crater/target/debug/build/koans-e1a0d9632c46dee3/build-script-build` (exit code: 101)
[INFO] [stderr] --- stderr
[INFO] [stderr] thread 'main' panicked at 'Read-only file system (os error 30)', build.rs:13:22
[INFO] [stderr] stack backtrace:
[INFO] [stderr]    0:     0x55d06492a2cb - backtrace::backtrace::libunwind::trace::h5d27dcba3b250cfe
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/libunwind.rs:88
[INFO] [stderr]    1:     0x55d06492a2cb - backtrace::backtrace::trace_unsynchronized::h239341a8b1cadbab
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/mod.rs:66
[INFO] [stderr]    2:     0x55d06492a2cb - std::sys_common::backtrace::_print::hb0e5dd39180a1838
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:47
[INFO] [stderr]    3:     0x55d06492a2cb - std::sys_common::backtrace::print::h9b385b2285f057b8
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:36
[INFO] [stderr]    4:     0x55d06492a2cb - std::panicking::default_hook::{{closure}}::he3310a15a78966b4
[INFO] [stderr]                                at src/libstd/panicking.rs:200
[INFO] [stderr]    5:     0x55d064929fa6 - std::panicking::default_hook::h2986f418df62eff4
[INFO] [stderr]                                at src/libstd/panicking.rs:214
[INFO] [stderr]    6:     0x55d06492a98d - std::panicking::rust_panic_with_hook::h15065386631d2a9d
[INFO] [stderr]                                at src/libstd/panicking.rs:477
[INFO] [stderr]    7:     0x55d06492a512 - std::panicking::continue_panic_fmt::h5e7761875fda3864
[INFO] [stderr]                                at src/libstd/panicking.rs:384
[INFO] [stderr]    8:     0x55d06492a45f - std::panicking::begin_panic_fmt::h23e4c9022d6fc089
[INFO] [stderr]                                at src/libstd/panicking.rs:339
[INFO] [stderr]    9:     0x55d064922a86 - build_script_build::main::hf9b4ee1f6e0758ef
[INFO] [stderr]                                at /opt/crater/workdir/build.rs:13
[INFO] [stderr]   10:     0x55d064922000 - std::rt::lang_start::{{closure}}::hcde600d7114240f6
[INFO] [stderr]                                at /rustc/452087b4bf18cece2d52d7cd8c9147195e5404bf/src/libstd/rt.rs:64
[INFO] [stderr]   11:     0x55d06492a3e3 - std::rt::lang_start_internal::{{closure}}::hbf4603a1e6e1424d
[INFO] [stderr]                                at src/libstd/rt.rs:49
[INFO] [stderr]   12:     0x55d06492a3e3 - std::panicking::try::do_call::h7642e0de797eeae0
[INFO] [stderr]                                at src/libstd/panicking.rs:296
[INFO] [stderr]   13:     0x55d06492c4aa - __rust_maybe_catch_panic
[INFO] [stderr]                                at src/libpanic_unwind/lib.rs:80
[INFO] [stderr]   14:     0x55d06492ae9d - std::panicking::try::h17f145530f8b5a3f
[INFO] [stderr]                                at src/libstd/panicking.rs:275
[INFO] [stderr]   15:     0x55d06492ae9d - std::panic::catch_unwind::hcee1b9b07ea0f9dc
[INFO] [stderr]                                at src/libstd/panic.rs:394
[INFO] [stderr]   16:     0x55d06492ae9d - std::rt::lang_start_internal::h82d44298f58b2cfd
[INFO] [stderr]                                at src/libstd/rt.rs:48
[INFO] [stderr]   17:     0x55d064921fd9 - std::rt::lang_start::hfff19cd5f9af01ca
[INFO] [stderr]                                at /rustc/452087b4bf18cece2d52d7cd8c9147195e5404bf/src/libstd/rt.rs:64
[INFO] [stderr]   18:     0x55d064922c6a - main
[INFO] [stderr]   19:     0x7f22825982e1 - __libc_start_main
[INFO] [stderr]   20:     0x55d064920cda - _start
[INFO] [stderr]   21:                0x0 - <unknown>
[INFO] [stderr] 
[INFO] running `"docker" "inspect" "e73d443134ca943d5b0a1f6da56e61f129653f5c1c45cf003c3736c9c7574ebd"`
[INFO] running `"docker" "rm" "-f" "e73d443134ca943d5b0a1f6da56e61f129653f5c1c45cf003c3736c9c7574ebd"`
[INFO] [stdout] e73d443134ca943d5b0a1f6da56e61f129653f5c1c45cf003c3736c9c7574ebd