[INFO] updating cached repository https://github.com/grenewode/i3switcher
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c6729586aeabaea1debd2d9f72d7e80e65125046
[INFO] checking grenewode/i3switcher against master#c724b67e1b474262917a5154d74e7072267593fe for pr-74315
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fgrenewode%2Fi3switcher" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/grenewode/i3switcher on toolchain c724b67e1b474262917a5154d74e7072267593fe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/grenewode/i3switcher
[INFO] finished tweaking git repo https://github.com/grenewode/i3switcher
[INFO] tweaked toml for git repo https://github.com/grenewode/i3switcher written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/grenewode/i3switcher already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 732b56be078679d7799731c2f54d1d2ce50ed8ba82ec8fd2c17387c2f720a354
[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" "732b56be078679d7799731c2f54d1d2ce50ed8ba82ec8fd2c17387c2f720a354", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "732b56be078679d7799731c2f54d1d2ce50ed8ba82ec8fd2c17387c2f720a354", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "732b56be078679d7799731c2f54d1d2ce50ed8ba82ec8fd2c17387c2f720a354", kill_on_drop: false }`
[INFO] [stdout] 732b56be078679d7799731c2f54d1d2ce50ed8ba82ec8fd2c17387c2f720a354
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-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@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 055fee255fa976d4219288c86ba6376b1a5c1051046fc205c32145d343d355e7
[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" "055fee255fa976d4219288c86ba6376b1a5c1051046fc205c32145d343d355e7", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.75
[INFO] [stderr]     Checking unicode-width v0.1.4
[INFO] [stderr]     Checking vec_map v0.8.0
[INFO] [stderr]     Checking strsim v0.6.0
[INFO] [stderr]     Checking byteorder v1.2.6
[INFO] [stderr]     Checking log v0.3.8
[INFO] [stderr]    Compiling ryu v0.2.6
[INFO] [stderr]     Checking textwrap v0.7.0
[INFO] [stderr]     Checking clap v2.26.0
[INFO] [stderr]     Checking serde_json v1.0.26
[INFO] [stderr]     Checking i3ipc v0.8.2
[INFO] [stderr]     Checking i3switcher v0.3.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:17:17
[INFO] [stdout]    |
[INFO] [stdout] 17 |             let mut iter = workspaces.iter().rev().skip(workspaces.len() - current_idx);
[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: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:17:17
[INFO] [stdout]    |
[INFO] [stdout] 17 |             let mut iter = workspaces.iter().rev().skip(workspaces.len() - current_idx);
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 15.95s
[INFO] running `Command { std: "docker" "inspect" "055fee255fa976d4219288c86ba6376b1a5c1051046fc205c32145d343d355e7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "055fee255fa976d4219288c86ba6376b1a5c1051046fc205c32145d343d355e7", kill_on_drop: false }`
[INFO] [stdout] 055fee255fa976d4219288c86ba6376b1a5c1051046fc205c32145d343d355e7