[INFO] cloning repository https://github.com/xldenis/creusot
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xldenis/creusot" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxldenis%2Fcreusot", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxldenis%2Fcreusot'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8537c7ec48b015232692b11fc1b91eadac92e288
[INFO] testing xldenis/creusot against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxldenis%2Fcreusot" "/workspace/builds/worker-36/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-36/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xldenis/creusot on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-36/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/xldenis/creusot
[INFO] finished tweaking git repo https://github.com/xldenis/creusot
[INFO] tweaked toml for git repo https://github.com/xldenis/creusot written to /workspace/builds/worker-36/source/Cargo.toml
[INFO] crate git repo https://github.com/xldenis/creusot already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded pretty v0.10.0
[INFO] [stderr]   Downloaded mktemp v0.4.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c21e4f9ac3cb7e787631ead3838b5ee3619865c973af15f32d728dff4081b67c
[INFO] running `Command { std: "docker" "start" "-a" "c21e4f9ac3cb7e787631ead3838b5ee3619865c973af15f32d728dff4081b67c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c21e4f9ac3cb7e787631ead3838b5ee3619865c973af15f32d728dff4081b67c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c21e4f9ac3cb7e787631ead3838b5ee3619865c973af15f32d728dff4081b67c", kill_on_drop: false }`
[INFO] [stdout] c21e4f9ac3cb7e787631ead3838b5ee3619865c973af15f32d728dff4081b67c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-36/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 35aaa5918b339a7ca43289d8c3bfe9d393509e9d9b989574ef4b35456fc7e63c
[INFO] running `Command { std: "docker" "start" "-a" "35aaa5918b339a7ca43289d8c3bfe9d393509e9d9b989574ef4b35456fc7e63c", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling libc v0.2.86
[INFO] [stderr]    Compiling syn v1.0.67
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]    Compiling serde v1.0.123
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling syn v1.0.49 (https://github.com/xldenis/syn?branch=spec-lang-2#0e08fccf)
[INFO] [stderr]    Compiling once_cell v1.5.2
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling arrayvec v0.5.2
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling typed-arena v2.0.1
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling regex-syntax v0.6.22
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling humantime v2.1.0
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling itoa v0.4.8
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling sequence_trie v0.3.6
[INFO] [stderr]    Compiling unescape v0.1.0
[INFO] [stderr]    Compiling why3tests v0.1.0 (/opt/rustwide/workdir/why3tests)
[INFO] [stderr]    Compiling thread_local v1.1.3
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling itertools v0.10.0
[INFO] [stderr]    Compiling heck v0.3.2
[INFO] [stderr]    Compiling pretty v0.10.0
[INFO] [stderr]    Compiling indexmap v1.6.1
[INFO] [stderr]    Compiling aho-corasick v0.7.15
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling uuid v0.8.2
[INFO] [stderr]    Compiling regex v1.4.3
[INFO] [stderr]    Compiling env_logger v0.8.3
[INFO] [stderr]    Compiling creusot-contracts-proc v0.1.0 (/opt/rustwide/workdir/creusot-contracts-proc)
[INFO] [stderr]    Compiling creusot-contracts v0.1.0 (/opt/rustwide/workdir/creusot-contracts)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> creusot-contracts/src/lib.rs:2:38
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(feature = "typechecker", feature(rustc_private), feature(box_patterns, box_syntax))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> creusot-contracts/src/lib.rs:2:62
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(feature = "typechecker", feature(rustc_private), feature(box_patterns, box_syntax))]
[INFO] [stdout]   |                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `creusot-contracts` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "35aaa5918b339a7ca43289d8c3bfe9d393509e9d9b989574ef4b35456fc7e63c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35aaa5918b339a7ca43289d8c3bfe9d393509e9d9b989574ef4b35456fc7e63c", kill_on_drop: false }`
[INFO] [stdout] 35aaa5918b339a7ca43289d8c3bfe9d393509e9d9b989574ef4b35456fc7e63c