[INFO] updating cached repository https://github.com/meh/miserve
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 18bf3ca945cffa8b6f97f088f04c918e741f7dd9
[INFO] testing meh/miserve against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmeh%2Fmiserve" "work/builds/worker-7/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/meh/miserve on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/meh/miserve
[INFO] removed path dependency servo from git repo https://github.com/meh/miserve
[INFO] finished tweaking git repo https://github.com/meh/miserve
[INFO] tweaked toml for git repo https://github.com/meh/miserve written to work/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/meh/miserve already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] error: the lock file /big/crater/work/builds/worker-7/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/tomaka/glutin`
[INFO] [stderr]     Updating git repository `https://github.com/servo/servo`
[INFO] [stderr]     Updating git repository `https://github.com/servo/osmesa-src`
[INFO] [stderr]     Updating git repository `https://github.com/servo/media`
[INFO] [stderr]     Updating git repository `https://github.com/servo/webxr`
[INFO] [stderr]     Updating git repository `https://github.com/servo/webrender`
[INFO] [stderr]     Updating git repository `https://github.com/servo/gaol`
[INFO] [stderr]     Updating git repository `https://github.com/servo/devices`
[INFO] [stderr]     Updating git repository `https://github.com/servo/fontsan`
[INFO] [stderr]     Updating git repository `https://github.com/pcwalton/signpost.git`
[INFO] [stderr]     Updating git repository `https://github.com/servo/rust-mozjs`
[INFO] [stderr]     Updating git repository `https://github.com/servo/mozjs`
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 8312dc329771f3587a31f20cf3b4e46f8b195f0544ee04b9bf3238ed70da23a3
[INFO] running `"docker" "start" "-a" "8312dc329771f3587a31f20cf3b4e46f8b195f0544ee04b9bf3238ed70da23a3"`
[INFO] [stderr]    Compiling serde v1.0.88
[INFO] [stderr]    Compiling x11 v2.18.1
[INFO] [stderr]    Compiling jobserver v0.1.17
[INFO] [stderr]    Compiling memmap v0.7.0
[INFO] [stderr]    Compiling shared_library v0.1.9
[INFO] [stderr]    Compiling raw-window-handle v0.1.2
[INFO] [stderr]    Compiling ordered-float v1.0.2
[INFO] [stderr]    Compiling nix v0.14.1
[INFO] [stderr]    Compiling gl_generator v0.13.1
[INFO] [stderr]    Compiling serde_derive v1.0.88
[INFO] [stderr]    Compiling mio-extras v2.0.5
[INFO] [stderr]    Compiling x11-dl v2.18.4
[INFO] [stderr]    Compiling derivative v1.0.3
[INFO] [stderr]    Compiling env_logger v0.7.0
[INFO] [stderr]    Compiling osmesa-sys v0.1.2
[INFO] [stderr]    Compiling cc v1.0.45
[INFO] [stderr]    Compiling rusttype v0.8.1
[INFO] [stderr]    Compiling rusttype v0.7.9
[INFO] [stderr]    Compiling andrew v0.2.1
[INFO] [stderr]    Compiling glutin_egl_sys v0.1.3 (https://github.com/tomaka/glutin#e7cb817b)
[INFO] [stderr]    Compiling glutin_glx_sys v0.1.5 (https://github.com/tomaka/glutin#e7cb817b)
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling dlib v0.4.1
[INFO] [stderr]    Compiling wayland-sys v0.23.6
[INFO] [stderr]    Compiling calloop v0.4.4
[INFO] [stderr]    Compiling wayland-commons v0.23.6
[INFO] [stderr]    Compiling wayland-client v0.23.6
[INFO] [stderr]    Compiling wayland-protocols v0.23.6
[INFO] [stderr]    Compiling smithay-client-toolkit v0.6.4
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-0.6.10/lib.rs:33:32
[INFO] [stderr]    |
[INFO] [stderr] 33 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[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 `smallvec`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "8312dc329771f3587a31f20cf3b4e46f8b195f0544ee04b9bf3238ed70da23a3"`
[INFO] running `"docker" "rm" "-f" "8312dc329771f3587a31f20cf3b4e46f8b195f0544ee04b9bf3238ed70da23a3"`
[INFO] [stdout] 8312dc329771f3587a31f20cf3b4e46f8b195f0544ee04b9bf3238ed70da23a3