[INFO] cloning repository https://github.com/Ibexian/char_predictor
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Ibexian/char_predictor" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIbexian%2Fchar_predictor", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIbexian%2Fchar_predictor'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4a75007895fc1f57326754287a21332c038fdf0f
[INFO] checking Ibexian/char_predictor against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIbexian%2Fchar_predictor" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Ibexian/char_predictor on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Ibexian/char_predictor
[INFO] finished tweaking git repo https://github.com/Ibexian/char_predictor
[INFO] tweaked toml for git repo https://github.com/Ibexian/char_predictor written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/Ibexian/char_predictor already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "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] 759193b650ecefdae5616cea3d1ff479352ceb21c5d4d5be0a1071e8dbf1129e
[INFO] running `Command { std: "docker" "start" "-a" "759193b650ecefdae5616cea3d1ff479352ceb21c5d4d5be0a1071e8dbf1129e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "759193b650ecefdae5616cea3d1ff479352ceb21c5d4d5be0a1071e8dbf1129e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "759193b650ecefdae5616cea3d1ff479352ceb21c5d4d5be0a1071e8dbf1129e", kill_on_drop: false }`
[INFO] [stdout] 759193b650ecefdae5616cea3d1ff479352ceb21c5d4d5be0a1071e8dbf1129e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c5c0dde43f576e7b430de3e92deef602160c0e85475c2c63c47312f18d6f96df
[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" "c5c0dde43f576e7b430de3e92deef602160c0e85475c2c63c47312f18d6f96df", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.20
[INFO] [stderr]    Compiling pkg-config v0.3.13
[INFO] [stderr]    Compiling proc-macro2 v0.4.13
[INFO] [stderr]    Compiling serde v1.0.74
[INFO] [stderr]    Compiling ryu v0.2.5
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.17
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]    Compiling itoa v0.4.2
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling num-traits v0.2.5
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]     Checking winapi v0.2.8
[INFO] [stderr]     Checking byteorder v1.2.4
[INFO] [stderr]    Compiling xattr v0.2.2
[INFO] [stderr]    Compiling filetime v0.2.1
[INFO] [stderr]    Compiling socket2 v0.3.7
[INFO] [stderr]    Compiling log v0.4.4
[INFO] [stderr]    Compiling tar v0.4.16
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking aligned_alloc v0.1.3
[INFO] [stdout] error[E0658]: use of unstable library feature 'proc_macro_def_site'
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.4.13/src/unstable.rs:359:27
[INFO] [stdout]     |
[INFO] [stdout] 359 |             Span::Nightly(proc_macro::Span::def_site())
[INFO] [stdout]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #54724 <https://github.com/rust-lang/rust/issues/54724> for more information
[INFO] [stdout]     = help: add `#![feature(proc_macro_def_site)]` to the crate attributes to enable
[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 E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2`.
[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] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "c5c0dde43f576e7b430de3e92deef602160c0e85475c2c63c47312f18d6f96df", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c5c0dde43f576e7b430de3e92deef602160c0e85475c2c63c47312f18d6f96df", kill_on_drop: false }`
[INFO] [stdout] c5c0dde43f576e7b430de3e92deef602160c0e85475c2c63c47312f18d6f96df