[INFO] cloning repository https://github.com/mxj4/typeholder
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mxj4/typeholder" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxj4%2Ftypeholder", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxj4%2Ftypeholder'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 08b588d63243f4720916d09f79b8f7a8bd556774
[INFO] testing mxj4/typeholder against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmxj4%2Ftypeholder" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mxj4/typeholder on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mxj4/typeholder
[INFO] finished tweaking git repo https://github.com/mxj4/typeholder
[INFO] tweaked toml for git repo https://github.com/mxj4/typeholder written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/mxj4/typeholder already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0a385831b26fa245d1c7357677ca5c25235bedec2f58397ec6e8869bbac5e761
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0a385831b26fa245d1c7357677ca5c25235bedec2f58397ec6e8869bbac5e761", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0a385831b26fa245d1c7357677ca5c25235bedec2f58397ec6e8869bbac5e761", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0a385831b26fa245d1c7357677ca5c25235bedec2f58397ec6e8869bbac5e761", kill_on_drop: false }`
[INFO] [stdout] 0a385831b26fa245d1c7357677ca5c25235bedec2f58397ec6e8869bbac5e761
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f66a8e70a237e3e0cf20ce2200392de7dd5c4dd5b389acc69f7bce40cecd5c99
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f66a8e70a237e3e0cf20ce2200392de7dd5c4dd5b389acc69f7bce40cecd5c99", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling pkg-config v0.3.9
[INFO] [stderr]    Compiling libc v0.2.29
[INFO] [stderr]    Compiling bitflags v0.9.1
[INFO] [stderr]    Compiling lazy_static v0.2.8
[INFO] [stderr]    Compiling gdk-pixbuf v0.1.3 (https://github.com/gtk-rs/gdk-pixbuf#cc1c9ab4)
[INFO] [stderr]    Compiling gio v0.1.3 (https://github.com/gtk-rs/gio#2b2b061b)
[INFO] [stderr]    Compiling cairo-rs v0.1.3 (https://github.com/gtk-rs/cairo#94c84e60)
[INFO] [stderr]    Compiling c_vec v1.2.1
[INFO] [stderr]    Compiling gdk v0.5.3 (https://github.com/gtk-rs/gdk#cdb612c7)
[INFO] [stderr]    Compiling either v1.1.0
[INFO] [stderr]    Compiling linked-hash-map v0.4.2
[INFO] [stderr]    Compiling gtk v0.1.3 (https://github.com/gtk-rs/gtk#6f83f435)
[INFO] [stderr]    Compiling typed-arena v1.3.0
[INFO] [stderr]    Compiling peresil v0.3.0
[INFO] [stderr]    Compiling gettext-rs v0.3.0
[INFO] [stderr]    Compiling sxd-document v0.2.3
[INFO] [stderr]    Compiling itertools v0.6.1
[INFO] [stderr]    Compiling glib-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling gobject-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling gio-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling cairo-sys-rs v0.3.4 (https://github.com/gtk-rs/cairo#94c84e60)
[INFO] [stderr]    Compiling gdk-pixbuf-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling pango-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling gdk-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling atk-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling gtk-sys v0.3.4 (https://github.com/gtk-rs/sys#af83826e)
[INFO] [stderr]    Compiling typeholder v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> build.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(slice_patterns)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `typeholder`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "f66a8e70a237e3e0cf20ce2200392de7dd5c4dd5b389acc69f7bce40cecd5c99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f66a8e70a237e3e0cf20ce2200392de7dd5c4dd5b389acc69f7bce40cecd5c99", kill_on_drop: false }`
[INFO] [stdout] f66a8e70a237e3e0cf20ce2200392de7dd5c4dd5b389acc69f7bce40cecd5c99