[INFO] fetching crate pidgin 0.4.0...
[INFO] testing pidgin-0.4.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate pidgin 0.4.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate pidgin 0.4.0 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 crates.io crate pidgin 0.4.0
[INFO] finished tweaking crates.io crate pidgin 0.4.0
[INFO] tweaked toml for crates.io crate pidgin 0.4.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0e80a28f1414714eb7df597fc72bc2e144732f7017ce69a9ac758d2c41fd7c44
[INFO] running `Command { std: "docker" "start" "-a" "0e80a28f1414714eb7df597fc72bc2e144732f7017ce69a9ac758d2c41fd7c44", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0e80a28f1414714eb7df597fc72bc2e144732f7017ce69a9ac758d2c41fd7c44", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0e80a28f1414714eb7df597fc72bc2e144732f7017ce69a9ac758d2c41fd7c44", kill_on_drop: false }`
[INFO] [stdout] 0e80a28f1414714eb7df597fc72bc2e144732f7017ce69a9ac758d2c41fd7c44
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c58396ccc421937e6442e7b86a475b266897c66c4da2177f8371e023c53c56e0
[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" "c58396ccc421937e6442e7b86a475b266897c66c4da2177f8371e023c53c56e0", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling serde_regex v0.4.0
[INFO] [stderr]    Compiling pidgin v0.4.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/pidgin.rs:601:38
[INFO] [stdout]     |
[INFO] [stdout] 601 |     fn find_character_classes(&self, mut phrases: Vec<Vec<Expression>>) -> Vec<Vec<Expression>> {
[INFO] [stdout]     |                                      ----^^^^^^^
[INFO] [stdout]     |                                      |
[INFO] [stdout]     |                                      help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 31.92s
[INFO] running `Command { std: "docker" "inspect" "c58396ccc421937e6442e7b86a475b266897c66c4da2177f8371e023c53c56e0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c58396ccc421937e6442e7b86a475b266897c66c4da2177f8371e023c53c56e0", kill_on_drop: false }`
[INFO] [stdout] c58396ccc421937e6442e7b86a475b266897c66c4da2177f8371e023c53c56e0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 99b5dcbc7f3017e228b8eee4207ab069e24ea974600033f977e035d2da3b3b0a
[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" "99b5dcbc7f3017e228b8eee4207ab069e24ea974600033f977e035d2da3b3b0a", kill_on_drop: false }`
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling oorandom v11.1.3
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling plotters v0.2.15
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]    Compiling serde_cbor v0.11.1
[INFO] [stderr]    Compiling criterion-plot v0.4.3
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/pidgin.rs:601:38
[INFO] [stdout]     |
[INFO] [stdout] 601 |     fn find_character_classes(&self, mut phrases: Vec<Vec<Expression>>) -> Vec<Vec<Expression>> {
[INFO] [stdout]     |                                      ----^^^^^^^
[INFO] [stdout]     |                                      |
[INFO] [stdout]     |                                      help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling regex-automata v0.1.9
[INFO] [stderr]    Compiling bstr v0.2.14
[INFO] [stderr]    Compiling tinytemplate v1.2.0
[INFO] [stderr]    Compiling csv v1.1.5
[INFO] [stderr]    Compiling criterion v0.3.3
[INFO] [stderr]    Compiling pidgin v0.4.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> tests/macro.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/pidgin.rs:601:38
[INFO] [stdout]     |
[INFO] [stdout] 601 |     fn find_character_classes(&self, mut phrases: Vec<Vec<Expression>>) -> Vec<Vec<Expression>> {
[INFO] [stdout]     |                                      ----^^^^^^^
[INFO] [stdout]     |                                      |
[INFO] [stdout]     |                                      help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[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 `pidgin`
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "99b5dcbc7f3017e228b8eee4207ab069e24ea974600033f977e035d2da3b3b0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "99b5dcbc7f3017e228b8eee4207ab069e24ea974600033f977e035d2da3b3b0a", kill_on_drop: false }`
[INFO] [stdout] 99b5dcbc7f3017e228b8eee4207ab069e24ea974600033f977e035d2da3b3b0a