[INFO] fetching crate next-gen 0.0.10...
[INFO] checking next-gen-0.0.10 against try#ffa4a0215752773248fb0f0a8092f1c3e7907e9e for pr-75585
[INFO] extracting crate next-gen 0.0.10 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate next-gen 0.0.10 on toolchain ffa4a0215752773248fb0f0a8092f1c3e7907e9e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate next-gen 0.0.10
[INFO] finished tweaking crates.io crate next-gen 0.0.10
[INFO] tweaked toml for crates.io crate next-gen 0.0.10 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded next-gen_proc-macro v0.0.10
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0dd69f3e7efcec2c639c647f75d173b694291e26a0b0615de88f9b841c9c6b77
[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" "0dd69f3e7efcec2c639c647f75d173b694291e26a0b0615de88f9b841c9c6b77", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0dd69f3e7efcec2c639c647f75d173b694291e26a0b0615de88f9b841c9c6b77", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0dd69f3e7efcec2c639c647f75d173b694291e26a0b0615de88f9b841c9c6b77", kill_on_drop: false }`
[INFO] [stdout] 0dd69f3e7efcec2c639c647f75d173b694291e26a0b0615de88f9b841c9c6b77
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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=forbid" "-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" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f0bef32bc2d1c3575a59ddd10b4824a2b0cc54af7efc6e8863e8c53f14f5172b
[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" "f0bef32bc2d1c3575a59ddd10b4824a2b0cc54af7efc6e8863e8c53f14f5172b", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.20
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.39
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling fstrings-proc-macro v0.2.3
[INFO] [stderr]    Compiling fstrings v0.2.3
[INFO] [stderr]    Compiling next-gen_proc-macro v0.0.10
[INFO] [stderr]     Checking next-gen v0.0.10 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unreachable expression
[INFO] [stdout]    --> src/tests.rs:212:21
[INFO] [stdout]     |
[INFO] [stdout] 208 | /                     loop {
[INFO] [stdout] 209 | |                         yield_!(current);
[INFO] [stdout] 210 | |                         current = current.checked_sub(1)?;
[INFO] [stdout] 211 | |                     }
[INFO] [stdout]     | |_____________________- any code following this expression is unreachable
[INFO] [stdout] 212 |                       None
[INFO] [stdout]     |                       ^^^^ unreachable expression
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: couldn't read tests/../src/proc_macro/doc_examples/generator.rs: No such file or directory (os error 2)
[INFO] [stdout]   --> tests/proc_macro.rs:8:17
[INFO] [stdout]    |
[INFO] [stdout] 8  | /                 include! {
[INFO] [stdout] 9  | |                     concat!(
[INFO] [stdout] 10 | |                         "../src/proc_macro/doc_examples/",
[INFO] [stdout] 11 | |                         stringify!($ident),
[INFO] [stdout] 12 | |                         ".rs",
[INFO] [stdout] 13 | |                     )
[INFO] [stdout] 14 | |                 }
[INFO] [stdout]    | |_________________^
[INFO] [stdout] ...
[INFO] [stdout] 19 | /     test_include! {
[INFO] [stdout] 20 | |         generator,
[INFO] [stdout] 21 | |         generator_desugared,
[INFO] [stdout] 22 | |     }
[INFO] [stdout]    | |_____- in this macro invocation
[INFO] [stdout]    |
[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] warning: function is never used: `return_iterator_with_concrete_dyn_type`
[INFO] [stdout]    --> src/tests.rs:190:8
[INFO] [stdout]     |
[INFO] [stdout] 190 |     fn return_iterator_with_concrete_dyn_type ()
[INFO] [stdout]     |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `next-gen`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "f0bef32bc2d1c3575a59ddd10b4824a2b0cc54af7efc6e8863e8c53f14f5172b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f0bef32bc2d1c3575a59ddd10b4824a2b0cc54af7efc6e8863e8c53f14f5172b", kill_on_drop: false }`
[INFO] [stdout] f0bef32bc2d1c3575a59ddd10b4824a2b0cc54af7efc6e8863e8c53f14f5172b