[INFO] crate core_rustc-serialize 0.3.20-v0.3.19patch1 is already in cache
[INFO] extracting crate core_rustc-serialize 0.3.20-v0.3.19patch1 into work/ex/beta-1.38-1/sources/1.37.0/reg/core_rustc-serialize/0.3.20-v0.3.19patch1
[INFO] extracting crate core_rustc-serialize 0.3.20-v0.3.19patch1 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/core_rustc-serialize/0.3.20-v0.3.19patch1
[INFO] validating manifest of core_rustc-serialize-0.3.20-v0.3.19patch1 on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of core_rustc-serialize-0.3.20-v0.3.19patch1 on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing core_rustc-serialize-0.3.20-v0.3.19patch1
[INFO] finished frobbing core_rustc-serialize-0.3.20-v0.3.19patch1
[INFO] frobbed toml for core_rustc-serialize-0.3.20-v0.3.19patch1 written to work/ex/beta-1.38-1/sources/1.37.0/reg/core_rustc-serialize/0.3.20-v0.3.19patch1/Cargo.toml
[INFO] started frobbing core_rustc-serialize-0.3.20-v0.3.19patch1
[INFO] finished frobbing core_rustc-serialize-0.3.20-v0.3.19patch1
[INFO] frobbed toml for core_rustc-serialize-0.3.20-v0.3.19patch1 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/core_rustc-serialize/0.3.20-v0.3.19patch1/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing core_rustc-serialize-0.3.20-v0.3.19patch1 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/core_rustc-serialize/0.3.20-v0.3.19patch1:/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-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 0e08c975aebdd36d1758345e56cb6b533797326c6c80ff3f2b3ff36f8a10ab4f
[INFO] running `"docker" "start" "-a" "0e08c975aebdd36d1758345e56cb6b533797326c6c80ff3f2b3ff36f8a10ab4f"`
[INFO] [stderr]    Compiling core_collections v0.3.20170409
[INFO] [stderr] error: failed to run custom build command for `core_collections v0.3.20170409`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/crater/target/debug/build/core_collections-7685013563b807a8/build-script-build` (exit code: 101)
[INFO] [stderr] --- stderr
[INFO] [stderr] thread 'main' panicked at 'Unknown compiler version, upgrade core_collections?', src/libcore/option.rs:1166:5
[INFO] [stderr] stack backtrace:
[INFO] [stderr]    0:     0x559264985a7b - backtrace::backtrace::libunwind::trace::h23ae608c8b906c69
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/libunwind.rs:88
[INFO] [stderr]    1:     0x559264985a7b - backtrace::backtrace::trace_unsynchronized::h65b3ea295a85fd48
[INFO] [stderr]                                at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.34/src/backtrace/mod.rs:66
[INFO] [stderr]    2:     0x559264985a7b - std::sys_common::backtrace::_print::h24f527b44b6cfc06
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:47
[INFO] [stderr]    3:     0x559264985a7b - std::sys_common::backtrace::print::h712608e4347fd64a
[INFO] [stderr]                                at src/libstd/sys_common/backtrace.rs:36
[INFO] [stderr]    4:     0x559264985a7b - std::panicking::default_hook::{{closure}}::h6c3d570c2b500048
[INFO] [stderr]                                at src/libstd/panicking.rs:200
[INFO] [stderr]    5:     0x559264985756 - std::panicking::default_hook::hb29963fb4747e0dd
[INFO] [stderr]                                at src/libstd/panicking.rs:214
[INFO] [stderr]    6:     0x55926498613d - std::panicking::rust_panic_with_hook::hd1236c3083de823a
[INFO] [stderr]                                at src/libstd/panicking.rs:477
[INFO] [stderr]    7:     0x559264985cc2 - std::panicking::continue_panic_fmt::he38ad41d6304a12c
[INFO] [stderr]                                at src/libstd/panicking.rs:384
[INFO] [stderr]    8:     0x559264985ba6 - rust_begin_unwind
[INFO] [stderr]                                at src/libstd/panicking.rs:311
[INFO] [stderr]    9:     0x55926499eaed - core::panicking::panic_fmt::h1bc6de43c92ad80c
[INFO] [stderr]                                at src/libcore/panicking.rs:85
[INFO] [stderr]   10:     0x55926499eb57 - core::option::expect_failed::h129ce0dbbd17b87d
[INFO] [stderr]                                at src/libcore/option.rs:1166
[INFO] [stderr]   11:     0x5592649570ea - core::option::Option<T>::expect::hc4e0f599e2908787
[INFO] [stderr]                                at /rustc/e450539c2a8d7f791268d699cbe45ab3e57d43a1/src/libcore/option.rs:345
[INFO] [stderr]   12:     0x5592649555cd - build_script_build::main::hfa759b311b846639
[INFO] [stderr]                                at /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/core_collections-0.3.20170409/build.rs:48
[INFO] [stderr]   13:     0x559264957740 - std::rt::lang_start::{{closure}}::hdef4156807f650ed
[INFO] [stderr]                                at /rustc/e450539c2a8d7f791268d699cbe45ab3e57d43a1/src/libstd/rt.rs:64
[INFO] [stderr]   14:     0x559264985b93 - std::rt::lang_start_internal::{{closure}}::hf367a5a6ae52b0ce
[INFO] [stderr]                                at src/libstd/rt.rs:49
[INFO] [stderr]   15:     0x559264985b93 - std::panicking::try::do_call::h9d779bc5e27e3284
[INFO] [stderr]                                at src/libstd/panicking.rs:296
[INFO] [stderr]   16:     0x55926498c17a - __rust_maybe_catch_panic
[INFO] [stderr]                                at src/libpanic_unwind/lib.rs:80
[INFO] [stderr]   17:     0x55926498664d - std::panicking::try::h4af22d9cb0afa351
[INFO] [stderr]                                at src/libstd/panicking.rs:275
[INFO] [stderr]   18:     0x55926498664d - std::panic::catch_unwind::hbb68a9ada87bfb97
[INFO] [stderr]                                at src/libstd/panic.rs:394
[INFO] [stderr]   19:     0x55926498664d - std::rt::lang_start_internal::hba9e09d74440ce4d
[INFO] [stderr]                                at src/libstd/rt.rs:48
[INFO] [stderr]   20:     0x559264957719 - std::rt::lang_start::hc75999dd78bb04bd
[INFO] [stderr]                                at /rustc/e450539c2a8d7f791268d699cbe45ab3e57d43a1/src/libstd/rt.rs:64
[INFO] [stderr]   21:     0x559264955dca - main
[INFO] [stderr]   22:     0x7ff722cf42e1 - __libc_start_main
[INFO] [stderr]   23:     0x55926494f3ca - _start
[INFO] [stderr]   24:                0x0 - <unknown>
[INFO] [stderr] 
[INFO] running `"docker" "inspect" "0e08c975aebdd36d1758345e56cb6b533797326c6c80ff3f2b3ff36f8a10ab4f"`
[INFO] running `"docker" "rm" "-f" "0e08c975aebdd36d1758345e56cb6b533797326c6c80ff3f2b3ff36f8a10ab4f"`
[INFO] [stdout] 0e08c975aebdd36d1758345e56cb6b533797326c6c80ff3f2b3ff36f8a10ab4f