[INFO] cloning repository https://github.com/Mcat12/backtrack
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Mcat12/backtrack" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMcat12%2Fbacktrack", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMcat12%2Fbacktrack'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9a37c73ecf8ae1343a37bfea66982263d88bb0e4
[INFO] checking Mcat12/backtrack against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMcat12%2Fbacktrack" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Mcat12/backtrack on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Mcat12/backtrack
[INFO] finished tweaking git repo https://github.com/Mcat12/backtrack
[INFO] tweaked toml for git repo https://github.com/Mcat12/backtrack written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Mcat12/backtrack already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded walkdir v2.2.7
[INFO] [stderr]   Downloaded byteorder v1.2.7
[INFO] [stderr]   Downloaded simplelog v0.5.3
[INFO] [stderr]   Downloaded same-file v1.0.4
[INFO] [stderr]   Downloaded redox_syscall v0.1.43
[INFO] [stderr]   Downloaded thread-scoped v1.0.2
[INFO] [stderr]   Downloaded failure_derive v0.1.3
[INFO] [stderr]   Downloaded quote v0.6.10
[INFO] [stderr]   Downloaded term v0.5.1
[INFO] [stderr]   Downloaded criterion-plot v0.2.5
[INFO] [stderr]   Downloaded rand v0.4.3
[INFO] [stderr]   Downloaded csv-core v0.1.4
[INFO] [stderr]   Downloaded cc v1.0.25
[INFO] [stderr]   Downloaded failure v0.1.3
[INFO] [stderr]   Downloaded csv v1.0.2
[INFO] [stderr]   Downloaded memchr v2.1.1
[INFO] [stderr]   Downloaded handlebars v0.32.4
[INFO] [stderr]   Downloaded proc-macro2 v0.4.24
[INFO] [stderr]   Downloaded syn v0.15.22
[INFO] [stderr]   Downloaded serde_derive v1.0.81
[INFO] [stderr]   Downloaded serde_json v1.0.33
[INFO] [stderr]   Downloaded num-traits v0.2.6
[INFO] [stderr]   Downloaded chrono v0.4.6
[INFO] [stderr]   Downloaded criterion v0.2.5
[INFO] [stderr]   Downloaded cast v0.2.2
[INFO] [stderr]   Downloaded criterion-stats v0.2.5
[INFO] [stderr]   Downloaded synstructure v0.10.1
[INFO] [stderr]   Downloaded serde v1.0.81
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e2380f6e4493a959225019e50b1bfc6aa0f2f0dfc409ad2fe22916d171d88955
[INFO] running `Command { std: "docker" "start" "-a" "e2380f6e4493a959225019e50b1bfc6aa0f2f0dfc409ad2fe22916d171d88955", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e2380f6e4493a959225019e50b1bfc6aa0f2f0dfc409ad2fe22916d171d88955", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2380f6e4493a959225019e50b1bfc6aa0f2f0dfc409ad2fe22916d171d88955", kill_on_drop: false }`
[INFO] [stdout] e2380f6e4493a959225019e50b1bfc6aa0f2f0dfc409ad2fe22916d171d88955
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7b2699f38e29cda267ccee94e6ec56da1a72fcc585b68be5ddeabab88cbd9bfb
[INFO] running `Command { std: "docker" "start" "-a" "7b2699f38e29cda267ccee94e6ec56da1a72fcc585b68be5ddeabab88cbd9bfb", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.45
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]    Compiling proc-macro2 v0.4.24
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling cc v1.0.25
[INFO] [stderr]    Compiling serde v1.0.81
[INFO] [stderr]    Compiling unicode-xid v0.0.4
[INFO] [stderr]    Compiling ryu v0.2.7
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]     Checking byteorder v1.2.7
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]    Compiling quote v0.3.15
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]    Compiling failure_derive v0.1.3
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling synom v0.11.3
[INFO] [stderr]     Checking regex-syntax v0.6.4
[INFO] [stderr]     Checking rustc-demangle v0.1.9
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling pest v1.0.6
[INFO] [stderr]     Checking utf8-ranges v1.0.2
[INFO] [stderr]     Checking cast v0.2.2
[INFO] [stderr]     Checking either v1.5.0
[INFO] [stderr]     Checking itoa v0.4.3
[INFO] [stderr]     Checking itertools v0.7.11
[INFO] [stderr]     Checking textwrap v0.10.0
[INFO] [stderr]     Checking term v0.5.1
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]     Checking thread-scoped v1.0.2
[INFO] [stderr]     Checking same-file v1.0.4
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking backtrack v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking walkdir v2.2.7
[INFO] [stderr]    Compiling backtrace-sys v0.1.24
[INFO] [stderr]    Compiling quote v0.6.10
[INFO] [stderr]     Checking itertools-num v0.1.3
[INFO] [stderr]    Compiling syn v0.15.22
[INFO] [stderr]     Checking criterion-plot v0.2.5
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking rand v0.4.3
[INFO] [stderr]     Checking num_cpus v1.8.0
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]    Compiling pest_derive v1.0.8
[INFO] [stderr]     Checking clap v2.32.0
[INFO] [stderr]     Checking aho-corasick v0.6.9
[INFO] [stderr]     Checking csv-core v0.1.4
[INFO] [stderr]     Checking chrono v0.4.6
[INFO] [stderr]     Checking criterion-stats v0.2.5
[INFO] [stderr]     Checking backtrace v0.3.9
[INFO] [stderr]     Checking simplelog v0.5.3
[INFO] [stderr]    Compiling synstructure v0.10.1
[INFO] [stderr]    Compiling serde_derive v1.0.81
[INFO] [stderr]     Checking serde_json v1.0.33
[INFO] [stderr]     Checking csv v1.0.2
[INFO] [stderr]     Checking handlebars v0.32.4
[INFO] [stderr]     Checking failure v0.1.3
[INFO] [stderr]     Checking criterion v0.2.5
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 25.85s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.2.5
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 3`
[INFO] running `Command { std: "docker" "inspect" "7b2699f38e29cda267ccee94e6ec56da1a72fcc585b68be5ddeabab88cbd9bfb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b2699f38e29cda267ccee94e6ec56da1a72fcc585b68be5ddeabab88cbd9bfb", kill_on_drop: false }`
[INFO] [stdout] 7b2699f38e29cda267ccee94e6ec56da1a72fcc585b68be5ddeabab88cbd9bfb
[INFO] checking Mcat12/backtrack against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMcat12%2Fbacktrack" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Mcat12/backtrack on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Mcat12/backtrack
[INFO] finished tweaking git repo https://github.com/Mcat12/backtrack
[INFO] tweaked toml for git repo https://github.com/Mcat12/backtrack written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/Mcat12/backtrack already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 12daa8c87dd84d47297586dbb964cc94dd07f22f9f45369eb5c223554939a56e
[INFO] running `Command { std: "docker" "start" "-a" "12daa8c87dd84d47297586dbb964cc94dd07f22f9f45369eb5c223554939a56e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "12daa8c87dd84d47297586dbb964cc94dd07f22f9f45369eb5c223554939a56e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12daa8c87dd84d47297586dbb964cc94dd07f22f9f45369eb5c223554939a56e", kill_on_drop: false }`
[INFO] [stdout] 12daa8c87dd84d47297586dbb964cc94dd07f22f9f45369eb5c223554939a56e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1cf7ae2a4893fa7e81141ab10d90f5764a8cde5e59d1a10f72d20b6fe3a2ef3d
[INFO] running `Command { std: "docker" "start" "-a" "1cf7ae2a4893fa7e81141ab10d90f5764a8cde5e59d1a10f72d20b6fe3a2ef3d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.45
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]    Compiling proc-macro2 v0.4.24
[INFO] [stderr]    Compiling num-traits v0.2.6
[INFO] [stderr]    Compiling cc v1.0.25
[INFO] [stderr]    Compiling serde v1.0.81
[INFO] [stderr]    Compiling num-integer v0.1.39
[INFO] [stderr]    Compiling ryu v0.2.7
[INFO] [stderr]    Compiling unicode-xid v0.0.4
[INFO] [stderr]    Compiling failure_derive v0.1.3
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling quote v0.3.15
[INFO] [stderr]     Checking byteorder v1.2.7
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling synom v0.11.3
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking regex-syntax v0.6.4
[INFO] [stderr]     Checking cast v0.2.2
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]     Checking rustc-demangle v0.1.9
[INFO] [stderr]     Checking unicode-width v0.1.5
[INFO] [stderr]     Checking utf8-ranges v1.0.2
[INFO] [stderr]     Checking either v1.5.0
[INFO] [stderr]    Compiling pest v1.0.6
[INFO] [stderr]     Checking itoa v0.4.3
[INFO] [stderr]     Checking textwrap v0.10.0
[INFO] [stderr]     Checking itertools v0.7.11
[INFO] [stderr]     Checking term v0.5.1
[INFO] [stderr]     Checking bitflags v1.0.4
[INFO] [stderr]     Checking same-file v1.0.4
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking thread-scoped v1.0.2
[INFO] [stderr]     Checking walkdir v2.2.7
[INFO] [stderr]     Checking backtrack v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling backtrace-sys v0.1.24
[INFO] [stderr]    Compiling quote v0.6.10
[INFO] [stderr]    Compiling syn v0.15.22
[INFO] [stderr]     Checking itertools-num v0.1.3
[INFO] [stderr]     Checking time v0.1.40
[INFO] [stderr]     Checking rand v0.4.3
[INFO] [stderr]     Checking num_cpus v1.8.0
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking clap v2.32.0
[INFO] [stderr]     Checking criterion-plot v0.2.5
[INFO] [stderr]    Compiling pest_derive v1.0.8
[INFO] [stderr]     Checking aho-corasick v0.6.9
[INFO] [stderr]     Checking csv-core v0.1.4
[INFO] [stderr]     Checking chrono v0.4.6
[INFO] [stderr]     Checking criterion-stats v0.2.5
[INFO] [stderr]     Checking backtrace v0.3.9
[INFO] [stderr]     Checking simplelog v0.5.3
[INFO] [stderr]    Compiling synstructure v0.10.1
[INFO] [stderr]     Checking serde_json v1.0.33
[INFO] [stderr]     Checking csv v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.81
[INFO] [stderr]     Checking handlebars v0.32.4
[INFO] [stderr]     Checking failure v0.1.3
[INFO] [stderr]     Checking criterion v0.2.5
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 18.57s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.2.5
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 3`
[INFO] running `Command { std: "docker" "inspect" "1cf7ae2a4893fa7e81141ab10d90f5764a8cde5e59d1a10f72d20b6fe3a2ef3d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1cf7ae2a4893fa7e81141ab10d90f5764a8cde5e59d1a10f72d20b6fe3a2ef3d", kill_on_drop: false }`
[INFO] [stdout] 1cf7ae2a4893fa7e81141ab10d90f5764a8cde5e59d1a10f72d20b6fe3a2ef3d