[INFO] updating cached repository https://github.com/wasimdhamriya/calculator-assignment
[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] 9722d2cf2af1cfe9d4baee483018edee6b322cbb
[INFO] checking wasimdhamriya/calculator-assignment against master#fdc0011561c6365c596dfd8fa1ef388162bc89c7 for pr-66504-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwasimdhamriya%2Fcalculator-assignment" "/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/wasimdhamriya/calculator-assignment on toolchain fdc0011561c6365c596dfd8fa1ef388162bc89c7
[INFO] running `"/workspace/cargo-home/bin/cargo" "+fdc0011561c6365c596dfd8fa1ef388162bc89c7" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/wasimdhamriya/calculator-assignment
[INFO] removed path dependency calculator from git repo https://github.com/wasimdhamriya/calculator-assignment
[INFO] finished tweaking git repo https://github.com/wasimdhamriya/calculator-assignment
[INFO] tweaked toml for git repo https://github.com/wasimdhamriya/calculator-assignment written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/wasimdhamriya/calculator-assignment already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+fdc0011561c6365c596dfd8fa1ef388162bc89c7" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] warning: dependency (calculator) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr] error: the lock file /workspace/builds/worker-3/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/workspace/cargo-home/bin/cargo" "+fdc0011561c6365c596dfd8fa1ef388162bc89c7" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+fdc0011561c6365c596dfd8fa1ef388162bc89c7" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] warning: dependency (calculator) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[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" "+fdc0011561c6365c596dfd8fa1ef388162bc89c7" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 8d4db194ab84dbd45cbc444223e2317236611a0ce6f893708519dcc43b9f46a4
[INFO] running `"docker" "start" "-a" "8d4db194ab84dbd45cbc444223e2317236611a0ce6f893708519dcc43b9f46a4"`
[INFO] [stderr] warning: dependency (calculator) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr]     Checking vec_map v0.0.1
[INFO] [stderr]     Checking calculator v0.0.1
[INFO] [stderr] error[E0635]: unknown feature `collections`
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/calculator-0.0.1/src/expr.rs:4:12
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(collections)]
[INFO] [stderr]   |            ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0635`.
[INFO] [stderr] error: could not compile `calculator`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "8d4db194ab84dbd45cbc444223e2317236611a0ce6f893708519dcc43b9f46a4"`
[INFO] running `"docker" "rm" "-f" "8d4db194ab84dbd45cbc444223e2317236611a0ce6f893708519dcc43b9f46a4"`
[INFO] [stdout] 8d4db194ab84dbd45cbc444223e2317236611a0ce6f893708519dcc43b9f46a4