[INFO] updating cached repository Mark-Simulacrum/async-fn-size
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Mark-Simulacrum/async-fn-size
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Mark-Simulacrum/async-fn-size" "work/ex/beta-1.38-1/sources/1.37.0/gh/Mark-Simulacrum/async-fn-size"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Mark-Simulacrum/async-fn-size'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Mark-Simulacrum/async-fn-size" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mark-Simulacrum/async-fn-size"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mark-Simulacrum/async-fn-size'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8e79d6ce891b95c700046c3b55f0988e77fd8228
[INFO] sha for GitHub repo Mark-Simulacrum/async-fn-size: 8e79d6ce891b95c700046c3b55f0988e77fd8228
[INFO] validating manifest of Mark-Simulacrum/async-fn-size 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 Mark-Simulacrum/async-fn-size 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 Mark-Simulacrum/async-fn-size
[INFO] finished frobbing Mark-Simulacrum/async-fn-size
[INFO] frobbed toml for Mark-Simulacrum/async-fn-size written to work/ex/beta-1.38-1/sources/1.37.0/gh/Mark-Simulacrum/async-fn-size/Cargo.toml
[INFO] started frobbing Mark-Simulacrum/async-fn-size
[INFO] finished frobbing Mark-Simulacrum/async-fn-size
[INFO] frobbed toml for Mark-Simulacrum/async-fn-size written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mark-Simulacrum/async-fn-size/Cargo.toml
[INFO] crate Mark-Simulacrum/async-fn-size already has a lockfile, it will not be regenerated
[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 Mark-Simulacrum/async-fn-size against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/Mark-Simulacrum/async-fn-size:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] 604a63b8358abccae528346c0ed4f3ca7d6a9cde65991c728d529806c069a273
[INFO] running `"docker" "start" "-a" "604a63b8358abccae528346c0ed4f3ca7d6a9cde65991c728d529806c069a273"`
[INFO] [stderr]    Compiling syn v0.15.39
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.47
[INFO] [stderr]    Compiling bumpalo v2.5.0
[INFO] [stderr]    Compiling wasm-bindgen v0.2.47
[INFO] [stderr]    Compiling wasm-bindgen-test-macro v0.2.47
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.47
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.47
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.47
[INFO] [stderr]    Compiling js-sys v0.3.24
[INFO] [stderr]    Compiling console_error_panic_hook v0.1.6
[INFO] [stderr]    Compiling wasm-bindgen-futures v0.3.24
[INFO] [stderr]    Compiling wasm-bindgen-test v0.2.47
[INFO] [stderr]    Compiling async-fn-size v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:11:1
[INFO] [stderr]    |
[INFO] [stderr] 11 | #![feature(async_await)]
[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 `async-fn-size`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "604a63b8358abccae528346c0ed4f3ca7d6a9cde65991c728d529806c069a273"`
[INFO] running `"docker" "rm" "-f" "604a63b8358abccae528346c0ed4f3ca7d6a9cde65991c728d529806c069a273"`
[INFO] [stdout] 604a63b8358abccae528346c0ed4f3ca7d6a9cde65991c728d529806c069a273