[INFO] fetching crate loalang 0.1.20...
[INFO] checking loalang-0.1.20 against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] extracting crate loalang 0.1.20 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate loalang 0.1.20 on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate loalang 0.1.20
[INFO] finished tweaking crates.io crate loalang 0.1.20
[INFO] tweaked toml for crates.io crate loalang 0.1.20 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate loalang 0.1.20 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f1a5e04a312e3993f0e1cd9b0aa4b32c0992f2d645d92f7fec4d87861a45d3c1
[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" "f1a5e04a312e3993f0e1cd9b0aa4b32c0992f2d645d92f7fec4d87861a45d3c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f1a5e04a312e3993f0e1cd9b0aa4b32c0992f2d645d92f7fec4d87861a45d3c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1a5e04a312e3993f0e1cd9b0aa4b32c0992f2d645d92f7fec4d87861a45d3c1", kill_on_drop: false }`
[INFO] [stdout] f1a5e04a312e3993f0e1cd9b0aa4b32c0992f2d645d92f7fec4d87861a45d3c1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2b672ce071b22e4599dbe739f02bc9234bbcdaf65c84597efb76d545603c5960
[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" "2b672ce071b22e4599dbe739f02bc9234bbcdaf65c84597efb76d545603c5960", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling num-bigint v0.2.2
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling unicode-segmentation v1.5.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking peekmore v0.4.0
[INFO] [stderr]     Checking strum v0.17.1
[INFO] [stderr]     Checking ngrammatic v0.3.1
[INFO] [stderr]    Compiling proc-macro2 v1.0.5
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling num-rational v0.2.2
[INFO] [stderr]    Compiling num-iter v0.1.39
[INFO] [stderr]    Compiling num-complex v0.2.3
[INFO] [stderr]    Compiling bincode v1.2.0
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling serde_derive v1.0.101
[INFO] [stderr]    Compiling strum_macros v0.17.1
[INFO] [stderr]     Checking serde v1.0.101
[INFO] [stderr]     Checking num v0.2.0
[INFO] [stderr]     Checking fraction v0.6.2
[INFO] [stderr]     Checking loalang v0.1.20 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0463]: can't find crate for `serde_yaml`
[INFO] [stdout]  --> src/lib/fixture_tests.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | extern crate serde_yaml;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `loalang`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/lib/vm/call_stack.rs:33:9
[INFO] [stdout]    |
[INFO] [stdout] 33 | /         std::mem::replace(
[INFO] [stdout] 34 | |             self,
[INFO] [stdout] 35 | |             CallStack(Some(Arc::new(StackFrame {
[INFO] [stdout] 36 | |                 parent,
[INFO] [stdout] ...  |
[INFO] [stdout] 41 | |             }))),
[INFO] [stdout] 42 | |         );
[INFO] [stdout]    | |__________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/lib/vm/call_stack.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |         std::mem::replace(self, CallStack(parent));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/lib/optimization/optimizer.rs:308:9
[INFO] [stdout]     |
[INFO] [stdout] 308 |         std::mem::replace(self, optimized);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2b672ce071b22e4599dbe739f02bc9234bbcdaf65c84597efb76d545603c5960", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2b672ce071b22e4599dbe739f02bc9234bbcdaf65c84597efb76d545603c5960", kill_on_drop: false }`
[INFO] [stdout] 2b672ce071b22e4599dbe739f02bc9234bbcdaf65c84597efb76d545603c5960