[INFO] updating cached repository https://github.com/Nelocage/rust_os
[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] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8a71f7de5db2380365167a55b263a88cb99b145f
[INFO] testing Nelocage/rust_os against master#28742a1146f10a4f09369baad027a464acb7a766 for pr-71274
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNelocage%2Frust_os" "/workspace/builds/worker-3/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Nelocage/rust_os on toolchain 28742a1146f10a4f09369baad027a464acb7a766
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/Nelocage/rust_os
[INFO] finished tweaking git repo https://github.com/Nelocage/rust_os
[INFO] tweaked toml for git repo https://github.com/Nelocage/rust_os written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/Nelocage/rust_os already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"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" "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" "+28742a1146f10a4f09369baad027a464acb7a766" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 52a5ede7cca15e54684eded6a7d18434a09f8522020e2df381020c90d9fab124
[INFO] running `"docker" "start" "-a" "52a5ede7cca15e54684eded6a7d18434a09f8522020e2df381020c90d9fab124"`
[INFO] [stderr]    Compiling remove_dir_all v0.5.1
[INFO] [stderr]    Compiling llvm-tools v0.1.1
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling zero v0.1.2
[INFO] [stderr]    Compiling ux v0.1.3
[INFO] [stderr]    Compiling bit_field v0.9.0
[INFO] [stderr]    Compiling usize_conversions v0.2.0
[INFO] [stderr]    Compiling font8x8 v0.2.4
[INFO] [stderr]    Compiling getopts v0.2.18
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling xmas-elf v0.6.2
[INFO] [stderr]    Compiling array-init v0.0.4
[INFO] [stderr]    Compiling bootloader v0.5.3
[INFO] [stderr]    Compiling pulldown-cmark v0.0.3
[INFO] [stderr]    Compiling skeptic v0.5.0
[INFO] [stderr]    Compiling fixedvec v0.2.3
[INFO] [stderr]    Compiling x86_64 v0.3.6
[INFO] [stderr]    Compiling blog_os v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: linking with `cc` failed: exit code: 1
[INFO] [stderr]   |
[INFO] [stderr]   = note: "cc" "-Wl,--as-needed" "-Wl,-z,noexecstack" "-m64" "-L" "/opt/rustwide/rustup-home/toolchains/28742a1146f10a4f09369baad027a464acb7a766/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.0.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.1.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.2.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.3.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.4.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.5.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.6.rcgu.o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.7.rcgu.o" "-o" "/opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/rustwide/target/debug/deps" "-L" "/opt/rustwide/rustup-home/toolchains/28742a1146f10a4f09369baad027a464acb7a766/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/opt/rustwide/rustup-home/toolchains/28742a1146f10a4f09369baad027a464acb7a766/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-b6806800b307d4b9.rlib" "/opt/rustwide/rustup-home/toolchains/28742a1146f10a4f09369baad027a464acb7a766/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-e49d7651b12f7563.rlib" "/opt/rustwide/rustup-home/toolchains/28742a1146f10a4f09369baad027a464acb7a766/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-e8266574e26adcc3.rlib" "-Wl,-Bdynamic"
[INFO] [stderr]   = note: /opt/rustwide/target/debug/deps/blog_os-509bfc6dab9692b3.blog_os.5sl6foo2-cgu.6.rcgu.o: In function `_start':
[INFO] [stderr]           /opt/rustwide/workdir/src/main.rs:18: multiple definition of `_start'
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o:(.text+0x0): first defined here
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
[INFO] [stderr]           (.text+0x12): undefined reference to `__libc_csu_fini'
[INFO] [stderr]           (.text+0x19): undefined reference to `__libc_csu_init'
[INFO] [stderr]           (.text+0x20): undefined reference to `main'
[INFO] [stderr]           (.text+0x26): undefined reference to `__libc_start_main'
[INFO] [stderr]           collect2: error: ld returned 1 exit status
[INFO] [stderr]           
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `blog_os`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "52a5ede7cca15e54684eded6a7d18434a09f8522020e2df381020c90d9fab124"`
[INFO] running `"docker" "rm" "-f" "52a5ede7cca15e54684eded6a7d18434a09f8522020e2df381020c90d9fab124"`
[INFO] [stdout] 52a5ede7cca15e54684eded6a7d18434a09f8522020e2df381020c90d9fab124