[INFO] updating cached repository https://github.com/calebwin/fern
[INFO] running `Command { std: "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", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9e5da73a0152faa92f4cf96b504e42d82d9448f4
[INFO] testing calebwin/fern against beta-2020-07-24 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcalebwin%2Ffern" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/calebwin/fern on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/calebwin/fern
[INFO] finished tweaking git repo https://github.com/calebwin/fern
[INFO] tweaked toml for git repo https://github.com/calebwin/fern written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/calebwin/fern already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "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] b958f3c06b7a410dff939ddf9f89b2d6b23df702f0fec4981c348c1cc71de50e
[INFO] running `Command { std: "docker" "start" "-a" "b958f3c06b7a410dff939ddf9f89b2d6b23df702f0fec4981c348c1cc71de50e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b958f3c06b7a410dff939ddf9f89b2d6b23df702f0fec4981c348c1cc71de50e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b958f3c06b7a410dff939ddf9f89b2d6b23df702f0fec4981c348c1cc71de50e", kill_on_drop: false }`
[INFO] [stdout] b958f3c06b7a410dff939ddf9f89b2d6b23df702f0fec4981c348c1cc71de50e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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=warn" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--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] 0526ed6b90ffa89f15b24fb938ad207c7fba179e92646a825a1526778ad8eeb5
[INFO] running `Command { std: "docker" "start" "-a" "0526ed6b90ffa89f15b24fb938ad207c7fba179e92646a825a1526778ad8eeb5", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.29
[INFO] [stderr]    Compiling libc v0.2.48
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling cfg-if v0.1.6
[INFO] [stderr]    Compiling rustc-demangle v0.1.13
[INFO] [stderr]    Compiling backtrace v0.3.13
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling error-chain v0.12.0
[INFO] [stderr]    Compiling rsmt2 v0.10.0
[INFO] [stderr]    Compiling fern v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `SmtRes`
[INFO] [stdout]  --> src/main.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rsmt2::{SmtRes, Solver};
[INFO] [stdout]   |             ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: `rsmt2::example::simple::Cst` doesn't implement `std::fmt::Debug`
[INFO] [stdout]   --> src/main.rs:32:26
[INFO] [stdout]    |
[INFO] [stdout] 32 |         println!("{:?}", model);
[INFO] [stdout]    |                          ^^^^^ `rsmt2::example::simple::Cst` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `std::fmt::Debug` is not implemented for `rsmt2::example::simple::Cst`
[INFO] [stdout]    = note: required because of the requirements on the impl of `std::fmt::Debug` for `(std::string::String, std::string::String, rsmt2::example::simple::Cst)`
[INFO] [stdout]    = note: required because of the requirements on the impl of `std::fmt::Debug` for `std::vec::Vec<(std::string::String, std::string::String, rsmt2::example::simple::Cst)>`
[INFO] [stdout]    = note: required by `std::fmt::Debug::fmt`
[INFO] [stdout]    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `fern`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "0526ed6b90ffa89f15b24fb938ad207c7fba179e92646a825a1526778ad8eeb5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0526ed6b90ffa89f15b24fb938ad207c7fba179e92646a825a1526778ad8eeb5", kill_on_drop: false }`
[INFO] [stdout] 0526ed6b90ffa89f15b24fb938ad207c7fba179e92646a825a1526778ad8eeb5