[INFO] cloning repository https://github.com/abbychau/a_core
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/abbychau/a_core" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabbychau%2Fa_core", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabbychau%2Fa_core'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cf22720717cc9dbf9abc4e681d2827619c68646e
[INFO] testing abbychau/a_core against 1.47.0 for beta-1.48-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabbychau%2Fa_core" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/abbychau/a_core on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-3/source/.cargo/config
[INFO] started tweaking git repo https://github.com/abbychau/a_core
[INFO] finished tweaking git repo https://github.com/abbychau/a_core
[INFO] tweaked toml for git repo https://github.com/abbychau/a_core written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/abbychau/a_core already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ca49712ec4537879de00061fbe64176e8c8c5ad6b93f5c05259607e04fb35e8f
[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" "ca49712ec4537879de00061fbe64176e8c8c5ad6b93f5c05259607e04fb35e8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ca49712ec4537879de00061fbe64176e8c8c5ad6b93f5c05259607e04fb35e8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca49712ec4537879de00061fbe64176e8c8c5ad6b93f5c05259607e04fb35e8f", kill_on_drop: false }`
[INFO] [stdout] ca49712ec4537879de00061fbe64176e8c8c5ad6b93f5c05259607e04fb35e8f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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=warn" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 66c28206939a749cea99df4f81411f5023b758d2e1a12785afc3ff093eb70466
[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" "66c28206939a749cea99df4f81411f5023b758d2e1a12785afc3ff093eb70466", kill_on_drop: false }`
[INFO] [stderr]    Compiling bootloader v0.9.2
[INFO] [stderr]    Compiling volatile v0.2.6
[INFO] [stderr]    Compiling a_core v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `e`
[INFO] [stdout]    --> src/vga_buffer.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout] 115 |         Err(e)=>{writer.write_string("ello! ");}
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_e`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: linking with `cc` failed: exit code: 1
[INFO] [stdout]   |
[INFO] [stdout]   = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-Wl,--eh-frame-hdr" "-L" "/opt/rustwide/rustup-home/toolchains/1.47.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.0.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.1.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.10.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.11.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.12.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.13.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.14.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.2.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.3.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.4.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.5.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.6.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.7.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.8.rcgu.o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.9.rcgu.o" "-o" "/opt/rustwide/target/debug/deps/a_core-d725057284860ede" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/rustwide/target/debug/deps" "-L" "/opt/rustwide/rustup-home/toolchains/1.47.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/opt/rustwide/target/debug/deps/libvolatile-d2a07e95dfdef06c.rlib" "/opt/rustwide/rustup-home/toolchains/1.47.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-541997b56bb98660.rlib" "/opt/rustwide/rustup-home/toolchains/1.47.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-cdea3c81adab3d12.rlib" "/opt/rustwide/rustup-home/toolchains/1.47.0-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-cd9f15a39fb65cbc.rlib" "-Wl,-Bdynamic"
[INFO] [stdout]   = note: /usr/bin/ld: /opt/rustwide/target/debug/deps/a_core-d725057284860ede.a_core.762pew6m-cgu.8.rcgu.o: in function `_start':
[INFO] [stdout]           /opt/rustwide/workdir/src/main.rs:13: multiple definition of `_start'; /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o:(.text+0x0): first defined here
[INFO] [stdout]           /usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
[INFO] [stdout]           (.text+0x16): undefined reference to `__libc_csu_fini'
[INFO] [stdout]           /usr/bin/ld: (.text+0x1d): undefined reference to `__libc_csu_init'
[INFO] [stdout]           /usr/bin/ld: (.text+0x24): undefined reference to `main'
[INFO] [stdout]           /usr/bin/ld: (.text+0x2a): undefined reference to `__libc_start_main'
[INFO] [stdout]           collect2: error: ld returned 1 exit status
[INFO] [stdout]           
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `a_core`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "66c28206939a749cea99df4f81411f5023b758d2e1a12785afc3ff093eb70466", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66c28206939a749cea99df4f81411f5023b758d2e1a12785afc3ff093eb70466", kill_on_drop: false }`
[INFO] [stdout] 66c28206939a749cea99df4f81411f5023b758d2e1a12785afc3ff093eb70466
