[INFO] crate echoloc 0.1.10 is already in cache
[INFO] extracting crate echoloc 0.1.10 into work/ex/beta-1.38-1/sources/1.37.0/reg/echoloc/0.1.10
[INFO] extracting crate echoloc 0.1.10 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/echoloc/0.1.10
[INFO] validating manifest of echoloc-0.1.10 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 echoloc-0.1.10 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 echoloc-0.1.10
[INFO] finished frobbing echoloc-0.1.10
[INFO] frobbed toml for echoloc-0.1.10 written to work/ex/beta-1.38-1/sources/1.37.0/reg/echoloc/0.1.10/Cargo.toml
[INFO] started frobbing echoloc-0.1.10
[INFO] finished frobbing echoloc-0.1.10
[INFO] frobbed toml for echoloc-0.1.10 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/echoloc/0.1.10/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 echoloc-0.1.10 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-1/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/echoloc/0.1.10:/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] e9530a8e92933342579430957c4e0eff56072554bc498662f25ef54931bd8f26
[INFO] running `"docker" "start" "-a" "e9530a8e92933342579430957c4e0eff56072554bc498662f25ef54931bd8f26"`
[INFO] [stderr]    Compiling slog v2.5.2
[INFO] [stderr]    Compiling getset v0.0.7
[INFO] [stderr]    Compiling reqwest v0.9.20
[INFO] [stderr]    Compiling slog-try v0.2.0
[INFO] [stderr]    Compiling echoloc v0.1.10 (/opt/crater/workdir)
[INFO] [stderr] warning: unknown lint: `question_mark_macro_sep`
[INFO] [stderr]   --> src/lib.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 |     question_mark_macro_sep,
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unknown_lints)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]   --> src/lib.rs:14:1
[INFO] [stderr]    |
[INFO] [stderr] 14 | #![feature(crate_visibility_modifier)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `echoloc`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "e9530a8e92933342579430957c4e0eff56072554bc498662f25ef54931bd8f26"`
[INFO] running `"docker" "rm" "-f" "e9530a8e92933342579430957c4e0eff56072554bc498662f25ef54931bd8f26"`
[INFO] [stdout] e9530a8e92933342579430957c4e0eff56072554bc498662f25ef54931bd8f26