[INFO] fetching crate wasm-rpc-macros 0.2.12...
[INFO] extracting crate wasm-rpc-macros 0.2.12 into work/ex/beta-1.37-6/sources/1.36.0/reg/wasm-rpc-macros/0.2.12
[INFO] extracting crate wasm-rpc-macros 0.2.12 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/wasm-rpc-macros/0.2.12
[INFO] validating manifest of wasm-rpc-macros-0.2.12 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 wasm-rpc-macros-0.2.12 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 wasm-rpc-macros-0.2.12
[INFO] finished frobbing wasm-rpc-macros-0.2.12
[INFO] frobbed toml for wasm-rpc-macros-0.2.12 written to work/ex/beta-1.37-6/sources/1.36.0/reg/wasm-rpc-macros/0.2.12/Cargo.toml
[INFO] started frobbing wasm-rpc-macros-0.2.12
[INFO] finished frobbing wasm-rpc-macros-0.2.12
[INFO] frobbed toml for wasm-rpc-macros-0.2.12 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/wasm-rpc-macros/0.2.12/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing wasm-rpc-macros-0.2.12 against 1.36.0 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-7/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/wasm-rpc-macros/0.2.12:/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" "+1.36.0" "build" "--frozen"`
[INFO] [stdout] 83ee3c088cae73f9a3ad030d318c4962177777f4cd3ce0ecbbdc70faad9ce4e0
[INFO] running `"docker" "start" "-a" "83ee3c088cae73f9a3ad030d318c4962177777f4cd3ce0ecbbdc70faad9ce4e0"`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling syn v0.15.42
[INFO] [stderr]    Compiling wasm-rpc-macros v0.2.12 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | / #![feature(
[INFO] [stderr] 2 | |     type_ascription,
[INFO] [stderr] 3 | |     box_patterns,
[INFO] [stderr] 4 | |     proc_macro_quote,
[INFO] [stderr] 5 | |     rustc_private,
[INFO] [stderr] 6 | |     proc_macro_hygiene
[INFO] [stderr] 7 | | )]
[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 `wasm-rpc-macros`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "83ee3c088cae73f9a3ad030d318c4962177777f4cd3ce0ecbbdc70faad9ce4e0"`
[INFO] running `"docker" "rm" "-f" "83ee3c088cae73f9a3ad030d318c4962177777f4cd3ce0ecbbdc70faad9ce4e0"`
[INFO] [stdout] 83ee3c088cae73f9a3ad030d318c4962177777f4cd3ce0ecbbdc70faad9ce4e0