[INFO] fetching crate skipchannel 2.0.1...
[INFO] testing skipchannel-2.0.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate skipchannel 2.0.1 into /workspace/builds/worker-79/source
[INFO] validating manifest of crates.io crate skipchannel 2.0.1 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate skipchannel 2.0.1
[INFO] finished tweaking crates.io crate skipchannel 2.0.1
[INFO] tweaked toml for crates.io crate skipchannel 2.0.1 written to /workspace/builds/worker-79/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "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" "+1.55.0" "fetch" "--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-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5e4df6f40b1096abc7a87cdceef2e4d52f243d0a4399402c82abe5481355cf74
[INFO] running `Command { std: "docker" "start" "-a" "5e4df6f40b1096abc7a87cdceef2e4d52f243d0a4399402c82abe5481355cf74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e4df6f40b1096abc7a87cdceef2e4d52f243d0a4399402c82abe5481355cf74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e4df6f40b1096abc7a87cdceef2e4d52f243d0a4399402c82abe5481355cf74", kill_on_drop: false }`
[INFO] [stdout] 5e4df6f40b1096abc7a87cdceef2e4d52f243d0a4399402c82abe5481355cf74
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 489ba4bd7787e2ff35869b5f344ccc0eab39e157ea2c8ca0b3913dc384e5708c
[INFO] running `Command { std: "docker" "start" "-a" "489ba4bd7787e2ff35869b5f344ccc0eab39e157ea2c8ca0b3913dc384e5708c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling skipchannel v2.0.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.60s
[INFO] running `Command { std: "docker" "inspect" "489ba4bd7787e2ff35869b5f344ccc0eab39e157ea2c8ca0b3913dc384e5708c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "489ba4bd7787e2ff35869b5f344ccc0eab39e157ea2c8ca0b3913dc384e5708c", kill_on_drop: false }`
[INFO] [stdout] 489ba4bd7787e2ff35869b5f344ccc0eab39e157ea2c8ca0b3913dc384e5708c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8aa4f18d189f5ee6dba8a34435a432566bd0501a62452756ac0051b2316ca2eb
[INFO] running `Command { std: "docker" "start" "-a" "8aa4f18d189f5ee6dba8a34435a432566bd0501a62452756ac0051b2316ca2eb", kill_on_drop: false }`
[INFO] [stderr]    Compiling skipchannel v2.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: panic message is not a string literal
[INFO] [stdout]    --> src/lib.rs:105:36
[INFO] [stdout]     |
[INFO] [stdout] 105 |                 Err(err) => panic!(err),
[INFO] [stdout]     |                                    ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stdout]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stdout] help: add a "{}" format string to Display the message
[INFO] [stdout]     |
[INFO] [stdout] 105 |                 Err(err) => panic!("{}", err),
[INFO] [stdout]     |                                    ^^^^^
[INFO] [stdout] help: or use std::panic::panic_any instead
[INFO] [stdout]     |
[INFO] [stdout] 105 |                 Err(err) => std::panic::panic_any(err),
[INFO] [stdout]     |                             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.98s
[INFO] running `Command { std: "docker" "inspect" "8aa4f18d189f5ee6dba8a34435a432566bd0501a62452756ac0051b2316ca2eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8aa4f18d189f5ee6dba8a34435a432566bd0501a62452756ac0051b2316ca2eb", kill_on_drop: false }`
[INFO] [stdout] 8aa4f18d189f5ee6dba8a34435a432566bd0501a62452756ac0051b2316ca2eb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-79/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] d16955d4dfdf8786b473c12c55e842f9d6d79dbf0b6171af024f1a35ac71cd9a
[INFO] running `Command { std: "docker" "start" "-a" "d16955d4dfdf8786b473c12c55e842f9d6d79dbf0b6171af024f1a35ac71cd9a", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr] warning: panic message is not a string literal
[INFO] [stderr]    --> src/lib.rs:105:36
[INFO] [stderr]     |
[INFO] [stderr] 105 |                 Err(err) => panic!(err),
[INFO] [stderr]     |                                    ^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(non_fmt_panics)]` on by default
[INFO] [stderr]     = note: this usage of panic!() is deprecated; it will be a hard error in Rust 2021
[INFO] [stderr]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>
[INFO] [stderr] help: add a "{}" format string to Display the message
[INFO] [stderr]     |
[INFO] [stderr] 105 |                 Err(err) => panic!("{}", err),
[INFO] [stderr]     |                                    ^^^^^
[INFO] [stderr] help: or use std::panic::panic_any instead
[INFO] [stderr]     |
[INFO] [stderr] 105 |                 Err(err) => std::panic::panic_any(err),
[INFO] [stderr]     |                             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `skipchannel` (lib test) generated 1 warning
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.39s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/skipchannel-8a38fbce43da349e)
[INFO] [stdout] 
[INFO] [stdout] running 9 tests
[INFO] [stdout] test tests::skip_channel::allows_to_send_one_value ... ok
[INFO] [stdout] test tests::skip_channel::drop::does_not_drop_values_when_just_the_receiver_is_dropped ... ok
[INFO] [stdout] test tests::skip_channel::drop::does_not_drop_values_when_just_the_sender_is_dropped ... ok
[INFO] [stdout] test tests::skip_channel::allows_to_send_values_between_threads ... ok
[INFO] [stdout] test tests::skip_channel::drop::drops_unconsumed_values_on_subsequent_sends ... ok
[INFO] [stdout] test tests::skip_channel::returns_none_when_a_sent_value_is_already_consumed ... ok
[INFO] [stdout] test tests::skip_channel::skips_all_values_but_the_last ... ok
[INFO] [stdout] test tests::skip_channel::drop::value_is_dropped_when_sender_and_receiver_are_dropped ... ok
[INFO] [stdout] test tests::skip_channel::yields_none_when_nothing_is_sent ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 9 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.02s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests skipchannel
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs - (line 10) ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.86s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d16955d4dfdf8786b473c12c55e842f9d6d79dbf0b6171af024f1a35ac71cd9a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d16955d4dfdf8786b473c12c55e842f9d6d79dbf0b6171af024f1a35ac71cd9a", kill_on_drop: false }`
[INFO] [stdout] d16955d4dfdf8786b473c12c55e842f9d6d79dbf0b6171af024f1a35ac71cd9a