[INFO] fetching crate chainmap 0.1.2...
[INFO] checking chainmap-0.1.2 against try#b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b for pr-82781
[INFO] extracting crate chainmap 0.1.2 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate chainmap 0.1.2 on toolchain b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate chainmap 0.1.2
[INFO] finished tweaking crates.io crate chainmap 0.1.2
[INFO] tweaked toml for crates.io crate chainmap 0.1.2 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b" "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-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a7d460e7b9912de1a7f32194b79b755fd89dbb95b9742952b2cdf346e2e622f8
[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" "a7d460e7b9912de1a7f32194b79b755fd89dbb95b9742952b2cdf346e2e622f8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a7d460e7b9912de1a7f32194b79b755fd89dbb95b9742952b2cdf346e2e622f8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a7d460e7b9912de1a7f32194b79b755fd89dbb95b9742952b2cdf346e2e622f8", kill_on_drop: false }`
[INFO] [stdout] a7d460e7b9912de1a7f32194b79b755fd89dbb95b9742952b2cdf346e2e622f8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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=forbid" "-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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+b09a3e9a7a0ff7efb269ec0c13dcc0fd3cedcf6b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4e80238a734e62e90c954c1408941b11d6c86d9cf907fb7d941579a1149efb49
[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" "4e80238a734e62e90c954c1408941b11d6c86d9cf907fb7d941579a1149efb49", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking chainmap v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:331:9
[INFO] [stdout]     |
[INFO] [stdout] 331 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:331:9
[INFO] [stdout]     |
[INFO] [stdout] 331 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib.rs:416:9
[INFO] [stdout]     |
[INFO] [stdout] 416 |         std::mem::replace(&mut *self, oldlevel);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.03s
[INFO] running `Command { std: "docker" "inspect" "4e80238a734e62e90c954c1408941b11d6c86d9cf907fb7d941579a1149efb49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e80238a734e62e90c954c1408941b11d6c86d9cf907fb7d941579a1149efb49", kill_on_drop: false }`
[INFO] [stdout] 4e80238a734e62e90c954c1408941b11d6c86d9cf907fb7d941579a1149efb49