[INFO] updating cached repository https://github.com/Michael-F-Bryan/mdbook-epub
[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] 640a81209b9de4af8da082222f31f62dc9d21af0
[INFO] testing Michael-F-Bryan/mdbook-epub against master#28742a1146f10a4f09369baad027a464acb7a766 for pr-71274
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMichael-F-Bryan%2Fmdbook-epub" "/workspace/builds/worker-9/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Michael-F-Bryan/mdbook-epub 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/Michael-F-Bryan/mdbook-epub
[INFO] finished tweaking git repo https://github.com/Michael-F-Bryan/mdbook-epub
[INFO] tweaked toml for git repo https://github.com/Michael-F-Bryan/mdbook-epub written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/Michael-F-Bryan/mdbook-epub already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+28742a1146f10a4f09369baad027a464acb7a766" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"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=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] d59515a2455cc993035b6c6f11c522b17fa1877a790dcf82c63cc0239af07274
[INFO] running `"docker" "start" "-a" "d59515a2455cc993035b6c6f11c522b17fa1877a790dcf82c63cc0239af07274"`
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling itoa v0.4.5
[INFO] [stderr]    Compiling rustversion v1.0.2
[INFO] [stderr]    Compiling traitobject v0.1.0
[INFO] [stderr]    Compiling ucd-trie v0.1.2
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling typeable v0.1.2
[INFO] [stderr]    Compiling lazy_static v0.2.11
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling modifier v0.1.0
[INFO] [stderr]    Compiling serde v0.9.15
[INFO] [stderr]    Compiling adler32 v1.0.4
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling remove_dir_all v0.5.2
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling pulldown-cmark v0.6.1
[INFO] [stderr]    Compiling sequence_trie v0.3.6
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling same-file v1.0.6
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]    Compiling pulldown-cmark v0.7.0
[INFO] [stderr]    Compiling is-match v0.1.0
[INFO] [stderr]    Compiling glob v0.2.11
[INFO] [stderr]    Compiling shlex v0.1.1
[INFO] [stderr]    Compiling pest v0.3.3
[INFO] [stderr]    Compiling open v1.3.4
[INFO] [stderr]    Compiling bzip2-sys v0.1.7
[INFO] [stderr]    Compiling unicase v1.4.2
[INFO] [stderr]    Compiling getopts v0.2.21
[INFO] [stderr]    Compiling unreachable v0.1.1
[INFO] [stderr]    Compiling unsafe-any v0.4.2
[INFO] [stderr]    Compiling block-padding v0.1.5
[INFO] [stderr]    Compiling miniz_oxide v0.3.6
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling pest v2.1.2
[INFO] [stderr]    Compiling walkdir v2.3.1
[INFO] [stderr]    Compiling debug_unreachable v0.1.1
[INFO] [stderr]    Compiling inotify-sys v0.1.3
[INFO] [stderr]    Compiling filetime v0.2.8
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling gitignore v1.0.6
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling serde_json v1.0.48
[INFO] [stderr]    Compiling toml v0.5.6
[INFO] [stderr]    Compiling hashbrown v0.5.0
[INFO] [stderr]    Compiling typemap v0.3.3
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling regex v1.3.4
[INFO] [stderr]    Compiling mime v0.2.6
[INFO] [stderr]    Compiling mustache v0.9.0
[INFO] [stderr]    Compiling backtrace v0.3.44
[INFO] [stderr]    Compiling inotify v0.7.0
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling mio-extras v2.0.6
[INFO] [stderr]    Compiling plugin v0.2.6
[INFO] [stderr]    Compiling flate2 v1.0.13
[INFO] [stderr]    Compiling error-chain v0.12.2
[INFO] [stderr]    Compiling pest_meta v2.1.2
[INFO] [stderr]    Compiling sha-1 v0.8.2
[INFO] [stderr]    Compiling notify v4.0.15
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]    Compiling hyper v0.10.16
[INFO] [stderr]    Compiling uuid v0.8.1
[INFO] [stderr]    Compiling tempfile v3.1.0
[INFO] [stderr]    Compiling ws v0.9.1
[INFO] [stderr]    Compiling env_logger v0.6.2
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr] error: could not compile `regex`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name regex /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/regex-1.3.4/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 --cfg 'feature="aho-corasick"' --cfg 'feature="default"' --cfg 'feature="memchr"' --cfg 'feature="perf"' --cfg 'feature="perf-cache"' --cfg 'feature="perf-dfa"' --cfg 'feature="perf-inline"' --cfg 'feature="perf-literal"' --cfg 'feature="std"' --cfg 'feature="thread_local"' --cfg 'feature="unicode"' --cfg 'feature="unicode-age"' --cfg 'feature="unicode-bool"' --cfg 'feature="unicode-case"' --cfg 'feature="unicode-gencat"' --cfg 'feature="unicode-perl"' --cfg 'feature="unicode-script"' --cfg 'feature="unicode-segment"' -C metadata=ef730abd0be4aafc -C extra-filename=-ef730abd0be4aafc --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern aho_corasick=/opt/rustwide/target/debug/deps/libaho_corasick-dd2ac86c0ac78197.rmeta --extern memchr=/opt/rustwide/target/debug/deps/libmemchr-29d2c007361620fe.rmeta --extern regex_syntax=/opt/rustwide/target/debug/deps/libregex_syntax-f1ef5e203c87423f.rmeta --extern thread_local=/opt/rustwide/target/debug/deps/libthread_local-99a05dc3a68e4d67.rmeta --cap-lints allow --cap-lints=forbid` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `syn`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name syn /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/syn-0.15.44/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="extra-traits"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' -C metadata=976665fd22f6b0df -C extra-filename=-976665fd22f6b0df --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-83dd46554a579751.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-f46bba891338d68a.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-ff4fcdd9189ddc82.rmeta --cap-lints allow --cap-lints=forbid --cfg syn_can_match_trailing_dollar --cfg syn_can_use_thread_id --cfg syn_can_use_associated_constants --cfg syn_can_call_macro_by_path` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "d59515a2455cc993035b6c6f11c522b17fa1877a790dcf82c63cc0239af07274"`
[INFO] running `"docker" "rm" "-f" "d59515a2455cc993035b6c6f11c522b17fa1877a790dcf82c63cc0239af07274"`
[INFO] [stdout] d59515a2455cc993035b6c6f11c522b17fa1877a790dcf82c63cc0239af07274