[INFO] updating cached repository exul/ruma-identifiers-sample
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/exul/ruma-identifiers-sample
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/exul/ruma-identifiers-sample" "work/ex/beta-1.38-1/sources/1.37.0/gh/exul/ruma-identifiers-sample"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/exul/ruma-identifiers-sample'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/exul/ruma-identifiers-sample" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/exul/ruma-identifiers-sample"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/exul/ruma-identifiers-sample'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 2e32e2d394bca2825d39259873ebb69b23e64add
[INFO] sha for GitHub repo exul/ruma-identifiers-sample: 2e32e2d394bca2825d39259873ebb69b23e64add
[INFO] validating manifest of exul/ruma-identifiers-sample 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 exul/ruma-identifiers-sample 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 exul/ruma-identifiers-sample
[INFO] finished frobbing exul/ruma-identifiers-sample
[INFO] frobbed toml for exul/ruma-identifiers-sample written to work/ex/beta-1.38-1/sources/1.37.0/gh/exul/ruma-identifiers-sample/Cargo.toml
[INFO] started frobbing exul/ruma-identifiers-sample
[INFO] finished frobbing exul/ruma-identifiers-sample
[INFO] frobbed toml for exul/ruma-identifiers-sample written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/exul/ruma-identifiers-sample/Cargo.toml
[INFO] crate exul/ruma-identifiers-sample 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 exul/ruma-identifiers-sample 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-5/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/exul/ruma-identifiers-sample:/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] 13d989ea8208831b478239d11d72907fb72e9f6288eaeb8913787c01b6b7a768
[INFO] running `"docker" "start" "-a" "13d989ea8208831b478239d11d72907fb72e9f6288eaeb8913787c01b6b7a768"`
[INFO] [stderr]    Compiling libc v0.2.48
[INFO] [stderr]    Compiling memchr v2.1.3
[INFO] [stderr]    Compiling serde v1.0.86
[INFO] [stderr]    Compiling libsqlite3-sys v0.12.0
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling regex-syntax v0.6.5
[INFO] [stderr]    Compiling smallvec v0.6.8
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling quote v0.6.11
[INFO] [stderr]    Compiling unicode-normalization v0.1.8
[INFO] [stderr]    Compiling syn v0.15.26
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling aho-corasick v0.6.9
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]    Compiling url v1.7.2
[INFO] [stderr]    Compiling diesel_derives v1.4.0
[INFO] [stderr]    Compiling diesel v1.4.1
[INFO] [stderr]    Compiling migrations_internals v1.4.0
[INFO] [stderr]    Compiling ruma-identifiers v0.11.0 (http://github.com/ruma/ruma-identifiers#dbbc8be7)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/git/checkouts/ruma-identifiers-aff8848da78c58dc/dbbc8be/src/lib.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(try_from)]
[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 `ruma-identifiers`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "13d989ea8208831b478239d11d72907fb72e9f6288eaeb8913787c01b6b7a768"`
[INFO] running `"docker" "rm" "-f" "13d989ea8208831b478239d11d72907fb72e9f6288eaeb8913787c01b6b7a768"`
[INFO] [stdout] 13d989ea8208831b478239d11d72907fb72e9f6288eaeb8913787c01b6b7a768