[INFO] crate thin_cstr 0.1.0 is already in cache
[INFO] extracting crate thin_cstr 0.1.0 into work/ex/beta-1.37-6/sources/1.36.0/reg/thin_cstr/0.1.0
[INFO] extracting crate thin_cstr 0.1.0 into work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/thin_cstr/0.1.0
[INFO] validating manifest of thin_cstr-0.1.0 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 thin_cstr-0.1.0 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 thin_cstr-0.1.0
[INFO] finished frobbing thin_cstr-0.1.0
[INFO] frobbed toml for thin_cstr-0.1.0 written to work/ex/beta-1.37-6/sources/1.36.0/reg/thin_cstr/0.1.0/Cargo.toml
[INFO] started frobbing thin_cstr-0.1.0
[INFO] finished frobbing thin_cstr-0.1.0
[INFO] frobbed toml for thin_cstr-0.1.0 written to work/ex/beta-1.37-6/sources/beta-2019-07-23/reg/thin_cstr/0.1.0/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 thin_cstr-0.1.0 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-5/1.36.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/1.36.0/reg/thin_cstr/0.1.0:/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] 16430de0a76ef3953635d436888f2224cd6b55b4c188a06ba321d6353f346eec
[INFO] running `"docker" "start" "-a" "16430de0a76ef3953635d436888f2224cd6b55b4c188a06ba321d6353f346eec"`
[INFO] [stderr]    Compiling thin_cstr 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:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(extern_types)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: type annotations needed
[INFO] [stderr]    --> src/c_str.rs:832:27
[INFO] [stderr]     |
[INFO] [stderr] 832 |         (ptr as *const _).as_ref().expect("cannot convert a null pointer to a CStr")
[INFO] [stderr]     |                           ^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(tyvar_behind_raw_pointer)] on by default
[INFO] [stderr]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2018 edition!
[INFO] [stderr]     = note: for more information, see issue #46906 <https://github.com/rust-lang/rust/issues/46906>
[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 `thin_cstr`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "16430de0a76ef3953635d436888f2224cd6b55b4c188a06ba321d6353f346eec"`
[INFO] running `"docker" "rm" "-f" "16430de0a76ef3953635d436888f2224cd6b55b4c188a06ba321d6353f346eec"`
[INFO] [stdout] 16430de0a76ef3953635d436888f2224cd6b55b4c188a06ba321d6353f346eec