[INFO] cloning repository AleVul/kernel_playground
[INFO] running `"git" "clone" "--bare" "git://github.com/AleVul/kernel_playground.git" "work/cache/sources/gh/AleVul/kernel_playground"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/AleVul/kernel_playground'...
[INFO] running `"git" "clone" "work/cache/sources/gh/AleVul/kernel_playground" "work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/AleVul/kernel_playground"`
[INFO] [stderr] Cloning into 'work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/AleVul/kernel_playground'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/AleVul/kernel_playground" "work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/AleVul/kernel_playground"`
[INFO] [stderr] Cloning into 'work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/AleVul/kernel_playground'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] f2027c0a818473d324ee67f318f2235c5d7b7ab1
[INFO] sha for GitHub repo AleVul/kernel_playground: f2027c0a818473d324ee67f318f2235c5d7b7ab1
[INFO] validating manifest of AleVul/kernel_playground on toolchain master#c8865d8e195813ade6b84434ac9f8850e7112d1a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of AleVul/kernel_playground on toolchain try#e212b7d492c96d3837691ba29d32d5f468933fb8
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing AleVul/kernel_playground
[INFO] finished frobbing AleVul/kernel_playground
[INFO] frobbed toml for AleVul/kernel_playground written to work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/AleVul/kernel_playground/Cargo.toml
[INFO] started frobbing AleVul/kernel_playground
[INFO] finished frobbing AleVul/kernel_playground
[INFO] frobbed toml for AleVul/kernel_playground written to work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/AleVul/kernel_playground/Cargo.toml
[INFO] crate AleVul/kernel_playground already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] testing AleVul/kernel_playground against master#c8865d8e195813ade6b84434ac9f8850e7112d1a for pr-61629
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-61629/worker-6/master#c8865d8e195813ade6b84434ac9f8850e7112d1a:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/AleVul/kernel_playground:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "build" "--frozen"`
[INFO] [stdout] bf31f3d270bfd558ad0379e3a73c176694c61e49d7d0fc980dec7de6a3072d97
[INFO] running `"docker" "start" "-a" "bf31f3d270bfd558ad0379e3a73c176694c61e49d7d0fc980dec7de6a3072d97"`
[INFO] [stderr]    Compiling bit_field v0.9.0
[INFO] [stderr]    Compiling ux v0.1.2
[INFO] [stderr]    Compiling usize_conversions v0.2.0
[INFO] [stderr]    Compiling os_bootinfo v0.2.1
[INFO] [stderr]    Compiling bitflags v1.0.4
[INFO] [stderr]    Compiling x86_64 v0.2.11
[INFO] [stderr]    Compiling bootloader_precompiled v0.3.0
[INFO] [stderr]    Compiling kernel_playground v0.1.0 (/opt/crater/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/crater/rustup-home/toolchains/c8865d8e195813ade6b84434ac9f8850e7112d1a-alt/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.0.rcgu.o" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.1.rcgu.o" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.2.rcgu.o" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.3.rcgu.o" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.4.rcgu.o" "-o" "/opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/crater/target/debug/deps" "-L" "/opt/crater/rustup-home/toolchains/c8865d8e195813ade6b84434ac9f8850e7112d1a-alt/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-Wl,-Bstatic" "/opt/crater/target/debug/deps/libbootloader_precompiled-2fc35c793852ce74.rlib" "/opt/crater/target/debug/deps/libx86_64-3a3719d00f2a2caa.rlib" "/opt/crater/target/debug/deps/libux-04f5821d4b8e965a.rlib" "/opt/crater/target/debug/deps/libusize_conversions-5bdded72cf5c7f56.rlib" "/opt/crater/target/debug/deps/libos_bootinfo-6883e6295ce88624.rlib" "/opt/crater/target/debug/deps/libbit_field-e159bee715eaf616.rlib" "/opt/crater/target/debug/deps/libbitflags-289aea101accda3b.rlib" "/opt/crater/rustup-home/toolchains/c8865d8e195813ade6b84434ac9f8850e7112d1a-alt/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-5d5836de4a922af7.rlib" "/opt/crater/rustup-home/toolchains/c8865d8e195813ade6b84434ac9f8850e7112d1a-alt/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-0bd990bd23dec0da.rlib" "/opt/crater/rustup-home/toolchains/c8865d8e195813ade6b84434ac9f8850e7112d1a-alt/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-f5a50a9afbc6d167.rlib" "-Wl,-Bdynamic"
[INFO] [stderr]   = note: /opt/crater/target/debug/deps/kernel_playground-4af0ca9a04066331.kernel_playground.8j4z6ysb-cgu.3.rcgu.o: In function `_start':
[INFO] [stderr]           /opt/crater/workdir/src/main.rs:17: multiple definition of `_start'
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o:(.text+0x0): first defined here
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
[INFO] [stderr]           (.text+0x12): undefined reference to `__libc_csu_fini'
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
[INFO] [stderr]           (.text+0x19): undefined reference to `__libc_csu_init'
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
[INFO] [stderr]           (.text+0x20): undefined reference to `main'
[INFO] [stderr]           /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
[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 `kernel_playground`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "bf31f3d270bfd558ad0379e3a73c176694c61e49d7d0fc980dec7de6a3072d97"`
[INFO] running `"docker" "rm" "-f" "bf31f3d270bfd558ad0379e3a73c176694c61e49d7d0fc980dec7de6a3072d97"`
[INFO] [stdout] bf31f3d270bfd558ad0379e3a73c176694c61e49d7d0fc980dec7de6a3072d97