[INFO] cloning repository https://github.com/Idolf/syscall-challenge
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Idolf/syscall-challenge" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIdolf%2Fsyscall-challenge", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIdolf%2Fsyscall-challenge'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ec63f361e67560791d5209106eeac6ea40df8023
[INFO] checking Idolf/syscall-challenge against try#3bb2879ea9e58d65b875f9a98df44f4a43ce2597 for pr-85387
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FIdolf%2Fsyscall-challenge" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Idolf/syscall-challenge on toolchain 3bb2879ea9e58d65b875f9a98df44f4a43ce2597
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3bb2879ea9e58d65b875f9a98df44f4a43ce2597" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Idolf/syscall-challenge
[INFO] finished tweaking git repo https://github.com/Idolf/syscall-challenge
[INFO] tweaked toml for git repo https://github.com/Idolf/syscall-challenge written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/Idolf/syscall-challenge already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+3bb2879ea9e58d65b875f9a98df44f4a43ce2597" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating git repository `https://github.com/Idolf/nix.git`
[INFO] [stderr]     Updating git repository `https://github.com/rust-lang/libc`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded uuid v0.3.1
[INFO] [stderr]   Downloaded ipc-channel v0.6.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+3bb2879ea9e58d65b875f9a98df44f4a43ce2597" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a0e9e486fb552309a55729b275452d6c245b6978e49826c4441e0dc8c65274db
[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" "a0e9e486fb552309a55729b275452d6c245b6978e49826c4441e0dc8c65274db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a0e9e486fb552309a55729b275452d6c245b6978e49826c4441e0dc8c65274db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a0e9e486fb552309a55729b275452d6c245b6978e49826c4441e0dc8c65274db", kill_on_drop: false }`
[INFO] [stdout] a0e9e486fb552309a55729b275452d6c245b6978e49826c4441e0dc8c65274db
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+3bb2879ea9e58d65b875f9a98df44f4a43ce2597" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] 1f759a74c7ad7b703637b5ebbe6e11e942044e42abda0d4fbbcc585241b5ca86
[INFO] running `Command { std: "docker" "start" "-a" "1f759a74c7ad7b703637b5ebbe6e11e942044e42abda0d4fbbcc585241b5ca86", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.20
[INFO] [stderr]     Checking rustc-serialize v0.3.22
[INFO] [stderr]     Checking num-traits v0.1.36
[INFO] [stderr]     Checking cfg-if v0.1.0
[INFO] [stderr]     Checking lazy_static v0.2.2
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking bitflags v0.4.0
[INFO] [stderr]     Checking libc v0.2.20 (https://github.com/rust-lang/libc#bce927b3)
[INFO] [stderr]     Checking nix v0.8.0 (https://github.com/Idolf/nix.git?branch=ptrace-stuff#65f0d512)
[INFO] [stderr]     Checking rand v0.3.15
[INFO] [stderr]     Checking uuid v0.3.1
[INFO] [stderr]     Checking bincode v0.6.1
[INFO] [stderr]     Checking ipc-channel v0.6.0
[INFO] [stderr]     Checking syscall-challenge v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: getting the inner pointer of a temporary `CString`
[INFO] [stdout]   --> src/main.rs:95:69
[INFO] [stdout]    |
[INFO] [stdout] 95 |     assert!(unsafe { libc::rmdir(CString::new("/old_root").unwrap().as_ptr()) } == 0);
[INFO] [stdout]    |                                  ---------------------------------- ^^^^^^ this pointer will be invalid
[INFO] [stdout]    |                                  |
[INFO] [stdout]    |                                  this `CString` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(temporary_cstring_as_ptr)]` on by default
[INFO] [stdout]    = note: pointers do not have a lifetime; when calling `as_ptr` the `CString` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
[INFO] [stdout]    = help: for more information, see https://doc.rust-lang.org/reference/destructors.html
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: getting the inner pointer of a temporary `CString`
[INFO] [stdout]   --> src/main.rs:95:69
[INFO] [stdout]    |
[INFO] [stdout] 95 |     assert!(unsafe { libc::rmdir(CString::new("/old_root").unwrap().as_ptr()) } == 0);
[INFO] [stdout]    |                                  ---------------------------------- ^^^^^^ this pointer will be invalid
[INFO] [stdout]    |                                  |
[INFO] [stdout]    |                                  this `CString` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(temporary_cstring_as_ptr)]` on by default
[INFO] [stdout]    = note: pointers do not have a lifetime; when calling `as_ptr` the `CString` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
[INFO] [stdout]    = help: for more information, see https://doc.rust-lang.org/reference/destructors.html
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 6.70s
[INFO] running `Command { std: "docker" "inspect" "1f759a74c7ad7b703637b5ebbe6e11e942044e42abda0d4fbbcc585241b5ca86", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1f759a74c7ad7b703637b5ebbe6e11e942044e42abda0d4fbbcc585241b5ca86", kill_on_drop: false }`
[INFO] [stdout] 1f759a74c7ad7b703637b5ebbe6e11e942044e42abda0d4fbbcc585241b5ca86