[INFO] crate persistentcache_procmacro 0.0.3 is already in cache
[INFO] extracting crate persistentcache_procmacro 0.0.3 into work/ex/beta-1.37-6/sources/1.36.0/reg/persistentcache_procmacro/0.0.3
[INFO] extracting crate persistentcache_procmacro 0.0.3 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/persistentcache_procmacro/0.0.3
[INFO] validating manifest of persistentcache_procmacro-0.0.3 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 persistentcache_procmacro-0.0.3 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 persistentcache_procmacro-0.0.3
[INFO] finished frobbing persistentcache_procmacro-0.0.3
[INFO] frobbed toml for persistentcache_procmacro-0.0.3 written to work/ex/beta-1.37-6/sources/1.36.0/reg/persistentcache_procmacro/0.0.3/Cargo.toml
[INFO] started frobbing persistentcache_procmacro-0.0.3
[INFO] finished frobbing persistentcache_procmacro-0.0.3
[INFO] frobbed toml for persistentcache_procmacro-0.0.3 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/persistentcache_procmacro/0.0.3/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 persistentcache_procmacro-0.0.3 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-0/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/persistentcache_procmacro/0.0.3:/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] 6851ac044ce6c9f2f02f71ed91ccb5db4cbfa1946f87c5df9cc0c8f92d310356
[INFO] running `"docker" "start" "-a" "6851ac044ce6c9f2f02f71ed91ccb5db4cbfa1946f87c5df9cc0c8f92d310356"`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling futures-await-quote v0.4.0
[INFO] [stderr]    Compiling futures-await-synom v0.12.0
[INFO] [stderr]    Compiling futures-await-syn v0.12.0
[INFO] [stderr]    Compiling persistentcache_procmacro v0.0.3 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:15:1
[INFO] [stderr]    |
[INFO] [stderr] 15 | #![feature(proc_macro)]
[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 `persistentcache_procmacro`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "6851ac044ce6c9f2f02f71ed91ccb5db4cbfa1946f87c5df9cc0c8f92d310356"`
[INFO] running `"docker" "rm" "-f" "6851ac044ce6c9f2f02f71ed91ccb5db4cbfa1946f87c5df9cc0c8f92d310356"`
[INFO] [stdout] 6851ac044ce6c9f2f02f71ed91ccb5db4cbfa1946f87c5df9cc0c8f92d310356