[INFO] crate jam 0.0.1 is already in cache
[INFO] testing jam-0.0.1 against 1.38.0 for beta-1.39-1
[INFO] extracting crate jam 0.0.1 into work/builds/worker-7/source
[INFO] validating manifest of crates.io crate jam 0.0.1 on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate jam 0.0.1
[INFO] finished tweaking crates.io crate jam 0.0.1
[INFO] tweaked toml for crates.io crate jam 0.0.1 written to work/builds/worker-7/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] c1645c32a5ea49160c9589042cf9e4e92923ea47a54a718bcd2888a85f8a5969
[INFO] running `"docker" "start" "-a" "c1645c32a5ea49160c9589042cf9e4e92923ea47a54a718bcd2888a85f8a5969"`
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling bincode v0.7.0
[INFO] [stderr]    Compiling serde_codegen_internals v0.14.2
[INFO] [stderr]    Compiling serde_derive v0.9.15
[INFO] [stderr]    Compiling jam_derive v0.0.1
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/jam_derive-0.0.1/src/lib.rs:34:1
[INFO] [stderr]    |
[INFO] [stderr] 34 | #![feature(proc_macro, proc_macro_lib)]
[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 `jam_derive`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "c1645c32a5ea49160c9589042cf9e4e92923ea47a54a718bcd2888a85f8a5969"`
[INFO] running `"docker" "rm" "-f" "c1645c32a5ea49160c9589042cf9e4e92923ea47a54a718bcd2888a85f8a5969"`
[INFO] [stdout] c1645c32a5ea49160c9589042cf9e4e92923ea47a54a718bcd2888a85f8a5969