[INFO] updating cached repository https://github.com/techno-tanoC/knock_down
[INFO] running `"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"`
[INFO] [stderr] From https://github.com/techno-tanoC/knock_down
[INFO] [stderr]    72d45f0..0c85509  master     -> master
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 0c855095e9dea7ac9ac465ea0c390c654d650f1a
[INFO] checking techno-tanoC/knock_down against try#3ae4c050387df9f7fbb379ee90ce8bf05e566870 for pr-70872
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftechno-tanoC%2Fknock_down" "/workspace/builds/worker-7/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/techno-tanoC/knock_down on toolchain 3ae4c050387df9f7fbb379ee90ce8bf05e566870
[INFO] running `"/workspace/cargo-home/bin/cargo" "+3ae4c050387df9f7fbb379ee90ce8bf05e566870" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/techno-tanoC/knock_down
[INFO] finished tweaking git repo https://github.com/techno-tanoC/knock_down
[INFO] tweaked toml for git repo https://github.com/techno-tanoC/knock_down written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/techno-tanoC/knock_down already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+3ae4c050387df9f7fbb379ee90ce8bf05e566870" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "/opt/rustwide/cargo-home/bin/cargo" "+3ae4c050387df9f7fbb379ee90ce8bf05e566870" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 564c7103f81d5eea0ee7c58dd22d84283629ff47b2c797163b3de11f273d46ee
[INFO] running `"docker" "start" "-a" "564c7103f81d5eea0ee7c58dd22d84283629ff47b2c797163b3de11f273d46ee"`
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `x86_64-unknown-linux-musl` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: could not compile `cfg-if`.
[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[E0463]: can't find crate for `std`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `x86_64-unknown-linux-musl` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: could not compile `slab`.
[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 `"docker" "inspect" "564c7103f81d5eea0ee7c58dd22d84283629ff47b2c797163b3de11f273d46ee"`
[INFO] running `"docker" "rm" "-f" "564c7103f81d5eea0ee7c58dd22d84283629ff47b2c797163b3de11f273d46ee"`
[INFO] [stdout] 564c7103f81d5eea0ee7c58dd22d84283629ff47b2c797163b3de11f273d46ee