[INFO] fetching crate rocket_contrib_codegen 0.4.2...
[INFO] extracting crate rocket_contrib_codegen 0.4.2 into work/ex/beta-1.37-6/sources/1.36.0/reg/rocket_contrib_codegen/0.4.2
[INFO] extracting crate rocket_contrib_codegen 0.4.2 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rocket_contrib_codegen/0.4.2
[INFO] validating manifest of rocket_contrib_codegen-0.4.2 on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of rocket_contrib_codegen-0.4.2 on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing rocket_contrib_codegen-0.4.2
[INFO] finished frobbing rocket_contrib_codegen-0.4.2
[INFO] frobbed toml for rocket_contrib_codegen-0.4.2 written to work/ex/beta-1.37-6/sources/1.36.0/reg/rocket_contrib_codegen/0.4.2/Cargo.toml
[INFO] started frobbing rocket_contrib_codegen-0.4.2
[INFO] finished frobbing rocket_contrib_codegen-0.4.2
[INFO] frobbed toml for rocket_contrib_codegen-0.4.2 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rocket_contrib_codegen/0.4.2/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing rocket_contrib_codegen-0.4.2 against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rocket_contrib_codegen/0.4.2:/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=warn" "-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" "+beta-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 67c5ad6456ee2fea9e642d025df2ba584c42a6c75869e3ffecc87e366d132a8c
[INFO] running `"docker" "start" "-a" "67c5ad6456ee2fea9e642d025df2ba584c42a6c75869e3ffecc87e366d132a8c"`
[INFO] [stderr]    Compiling rocket_contrib_codegen v0.4.2 (/opt/crater/workdir)
[INFO] [stderr]    Compiling syn v0.15.42
[INFO] [stderr] error: failed to run custom build command for `rocket_contrib_codegen v0.4.2 (/opt/crater/workdir)`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/crater/target/debug/build/rocket_contrib_codegen-8af760b50cdebd1a/build-script-build` (exit code: 101)
[INFO] [stderr] --- stderr
[INFO] [stderr] Error: Rocket requires a 'dev' or 'nightly' version of rustc.
[INFO] [stderr] Installed version: 1.37.0 (2019-07-22)
[INFO] [stderr] Minimum required:  1.31.0-nightly (2018-10-05)
[INFO] [stderr] See the getting started guide (https://rocket.rs/v0.5/guide/getting-started/) for more information.
[INFO] [stderr] thread 'main' panicked at 'Aborting compilation due to incompatible compiler.', build.rs:29:13
[INFO] [stderr] stack backtrace:
[INFO] [stderr]    0:     0x55942a977d7b - backtrace::backtrace::libunwind::trace::h5dfa5d4c5feed6dc
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/libunwind.rs:88
[INFO] [stderr]    1:     0x55942a977d7b - backtrace::backtrace::trace_unsynchronized::hb731fe64f3fa469f
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.29/src/backtrace/mod.rs:66
[INFO] [stderr]    2:     0x55942a977d7b - std::sys_common::backtrace::_print::hf4fd45fe7ae4a250
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:47
[INFO] [stderr]    3:     0x55942a977d7b - std::sys_common::backtrace::print::h31646c3786c57441
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:36
[INFO] [stderr]    4:     0x55942a977d7b - std::panicking::default_hook::{{closure}}::hda785e768c746ae7
[INFO] [stderr]                                at src/libstd/panicking.rs:200
[INFO] [stderr]    5:     0x55942a977a57 - std::panicking::default_hook::h0c4b76f338614ef1
[INFO] [stderr]                                at src/libstd/panicking.rs:214
[INFO] [stderr]    6:     0x55942a978440 - std::panicking::rust_panic_with_hook::h096dff2cb12b67ce
[INFO] [stderr]                                at src/libstd/panicking.rs:477
[INFO] [stderr]    7:     0x55942a94bf74 - std::panicking::begin_panic::h895829bcf21018c3
[INFO] [stderr]                                at /rustc/61d1607e0f6a18bb4897d6f9b10abeac9e11eb8e/src/libstd/panicking.rs:411
[INFO] [stderr]    8:     0x55942a9476e5 - build_script_build::main::h907d993a9c48ee7a
[INFO] [stderr]                                at /opt/crater/workdir/build.rs:29
[INFO] [stderr]    9:     0x55942a949a00 - std::rt::lang_start::{{closure}}::ha51021b9ae57dc2d
[INFO] [stderr]                                at /rustc/61d1607e0f6a18bb4897d6f9b10abeac9e11eb8e/src/libstd/rt.rs:64
[INFO] [stderr]   10:     0x55942a977e93 - std::rt::lang_start_internal::{{closure}}::h055e1fdc5578d418
[INFO] [stderr]                                at src/libstd/rt.rs:49
[INFO] [stderr]   11:     0x55942a977e93 - std::panicking::try::do_call::h480cafa68c9928b4
[INFO] [stderr]                                at src/libstd/panicking.rs:296
[INFO] [stderr]   12:     0x55942a97e14a - __rust_maybe_catch_panic
[INFO] [stderr]                                at src/libpanic_unwind/lib.rs:82
[INFO] [stderr]   13:     0x55942a97894d - std::panicking::try::he0549d0299de204a
[INFO] [stderr]                                at src/libstd/panicking.rs:275
[INFO] [stderr]   14:     0x55942a97894d - std::panic::catch_unwind::h422dc2db98f03517
[INFO] [stderr]                                at src/libstd/panic.rs:394
[INFO] [stderr]   15:     0x55942a97894d - std::rt::lang_start_internal::h121de03325a3f900
[INFO] [stderr]                                at src/libstd/rt.rs:48
[INFO] [stderr]   16:     0x55942a9499d9 - std::rt::lang_start::hc3f4bcf467014868
[INFO] [stderr]                                at /rustc/61d1607e0f6a18bb4897d6f9b10abeac9e11eb8e/src/libstd/rt.rs:64
[INFO] [stderr]   17:     0x55942a947e0a - main
[INFO] [stderr]   18:     0x7fa394c532e1 - __libc_start_main
[INFO] [stderr]   19:     0x55942a946d8a - _start
[INFO] [stderr]   20:                0x0 - <unknown>
[INFO] [stderr] 
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "67c5ad6456ee2fea9e642d025df2ba584c42a6c75869e3ffecc87e366d132a8c"`
[INFO] running `"docker" "rm" "-f" "67c5ad6456ee2fea9e642d025df2ba584c42a6c75869e3ffecc87e366d132a8c"`
[INFO] [stdout] 67c5ad6456ee2fea9e642d025df2ba584c42a6c75869e3ffecc87e366d132a8c