[INFO] crate rebar 0.0.1 is already in cache
[INFO] extracting crate rebar 0.0.1 into work/ex/beta-1.37-6/sources/1.36.0/reg/rebar/0.0.1
[INFO] extracting crate rebar 0.0.1 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rebar/0.0.1
[INFO] validating manifest of rebar-0.0.1 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 rebar-0.0.1 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 rebar-0.0.1
[INFO] finished frobbing rebar-0.0.1
[INFO] frobbed toml for rebar-0.0.1 written to work/ex/beta-1.37-6/sources/1.36.0/reg/rebar/0.0.1/Cargo.toml
[INFO] started frobbing rebar-0.0.1
[INFO] finished frobbing rebar-0.0.1
[INFO] frobbed toml for rebar-0.0.1 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/rebar/0.0.1/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] testing rebar-0.0.1 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-4/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/rebar/0.0.1:/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] bac7754656091b7ae91e66d89fbe11065ecc7cb7757f1d50f845ce40d1c85561
[INFO] running `"docker" "start" "-a" "bac7754656091b7ae91e66d89fbe11065ecc7cb7757f1d50f845ce40d1c85561"`
[INFO] [stderr]    Compiling dirs-sys v0.3.4
[INFO] [stderr]    Compiling dirs v2.0.2
[INFO] [stderr]    Compiling term v0.6.0
[INFO] [stderr]    Compiling rebar v0.0.1 (/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(collections)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no function or associated item named `from_str` found for type `std::string::String` in the current scope
[INFO] [stderr]   --> src/lib.rs:25:28
[INFO] [stderr]    |
[INFO] [stderr] 25 |     let mut line = String::from_str("\r");
[INFO] [stderr]    |                            ^^^^^^^^ function or associated item not found in `std::string::String`
[INFO] [stderr]    |
[INFO] [stderr]    = help: items from traits can only be used if the trait is in scope
[INFO] [stderr] help: the following trait is implemented but not in scope, perhaps add a `use` for it:
[INFO] [stderr]    |
[INFO] [stderr] 4  | use std::str::FromStr;
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0554, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rebar`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "bac7754656091b7ae91e66d89fbe11065ecc7cb7757f1d50f845ce40d1c85561"`
[INFO] running `"docker" "rm" "-f" "bac7754656091b7ae91e66d89fbe11065ecc7cb7757f1d50f845ce40d1c85561"`
[INFO] [stdout] bac7754656091b7ae91e66d89fbe11065ecc7cb7757f1d50f845ce40d1c85561