[INFO] fetching crate ckb-std 0.7.2...
[INFO] checking ckb-std-0.7.2 against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] extracting crate ckb-std 0.7.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate ckb-std 0.7.2 on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ckb-std 0.7.2
[INFO] finished tweaking crates.io crate ckb-std 0.7.2
[INFO] tweaked toml for crates.io crate ckb-std 0.7.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate crates.io crate ckb-std 0.7.2 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 27ab2a5fe13e92cfc0fcc58743bebb129886f84c060ad82df89d2f94b91f8a13
[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" "27ab2a5fe13e92cfc0fcc58743bebb129886f84c060ad82df89d2f94b91f8a13", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "27ab2a5fe13e92cfc0fcc58743bebb129886f84c060ad82df89d2f94b91f8a13", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "27ab2a5fe13e92cfc0fcc58743bebb129886f84c060ad82df89d2f94b91f8a13", kill_on_drop: false }`
[INFO] [stdout] 27ab2a5fe13e92cfc0fcc58743bebb129886f84c060ad82df89d2f94b91f8a13
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] bab9bf30946ac3dea3a09cf002f97fd543a33906541eee1f56b34db29b3fe90f
[INFO] running `Command { std: "docker" "start" "-a" "bab9bf30946ac3dea3a09cf002f97fd543a33906541eee1f56b34db29b3fe90f", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling cc v1.0.56
[INFO] [stderr]     Checking buddy-alloc v0.4.1
[INFO] [stderr]     Checking molecule v0.6.0
[INFO] [stderr]     Checking ckb-standalone-types v0.0.1-pre.1
[INFO] [stderr]    Compiling ckb-std v0.7.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a0`
[INFO] [stdout]   --> src/syscalls.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |            ^^ help: if this is intentional, prefix it with an underscore: `_a0`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a1`
[INFO] [stdout]   --> src/syscalls.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                     ^^ help: if this is intentional, prefix it with an underscore: `_a1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a2`
[INFO] [stdout]   --> src/syscalls.rs:12:30
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                              ^^ help: if this is intentional, prefix it with an underscore: `_a2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a3`
[INFO] [stdout]   --> src/syscalls.rs:12:39
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                       ^^ help: if this is intentional, prefix it with an underscore: `_a3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a0`
[INFO] [stdout]   --> src/syscalls.rs:12:12
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |            ^^ help: if this is intentional, prefix it with an underscore: `_a0`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a1`
[INFO] [stdout]   --> src/syscalls.rs:12:21
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                     ^^ help: if this is intentional, prefix it with an underscore: `_a1`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a2`
[INFO] [stdout]   --> src/syscalls.rs:12:30
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                              ^^ help: if this is intentional, prefix it with an underscore: `_a2`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a3`
[INFO] [stdout]   --> src/syscalls.rs:12:39
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                       ^^ help: if this is intentional, prefix it with an underscore: `_a3`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a4`
[INFO] [stdout]   --> src/syscalls.rs:12:48
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                ^^ help: if this is intentional, prefix it with an underscore: `_a4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a5`
[INFO] [stdout]   --> src/syscalls.rs:12:57
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                         ^^ help: if this is intentional, prefix it with an underscore: `_a5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a6`
[INFO] [stdout]   --> src/syscalls.rs:12:66
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                                  ^^ help: if this is intentional, prefix it with an underscore: `_a6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a7`
[INFO] [stdout]   --> src/syscalls.rs:12:75
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                                           ^^ help: if this is intentional, prefix it with an underscore: `_a7`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a4`
[INFO] [stdout]   --> src/syscalls.rs:12:48
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                ^^ help: if this is intentional, prefix it with an underscore: `_a4`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a5`
[INFO] [stdout]   --> src/syscalls.rs:12:57
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                         ^^ help: if this is intentional, prefix it with an underscore: `_a5`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a6`
[INFO] [stdout]   --> src/syscalls.rs:12:66
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                                  ^^ help: if this is intentional, prefix it with an underscore: `_a6`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a7`
[INFO] [stdout]   --> src/syscalls.rs:12:75
[INFO] [stdout]    |
[INFO] [stdout] 12 | fn syscall(a0: u64, a1: u64, a2: u64, a3: u64, a4: u64, a5: u64, a6: u64, a7: u64) -> u64 {
[INFO] [stdout]    |                                                                           ^^ help: if this is intentional, prefix it with an underscore: `_a7`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/syscalls.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     unsafe { syscall(code as u64, 0, 0, 0, 0, 0, 0, SYS_EXIT) };
[INFO] [stdout]    |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/syscalls.rs:37:15
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let ret = unsafe {
[INFO] [stdout]    |               ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/syscalls.rs:416:5
[INFO] [stdout]     |
[INFO] [stdout] 416 |     unsafe {
[INFO] [stdout]     |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/syscalls.rs:471:15
[INFO] [stdout]     |
[INFO] [stdout] 471 |     let ret = unsafe {
[INFO] [stdout]     |               ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/syscalls.rs:19:5
[INFO] [stdout]    |
[INFO] [stdout] 19 |     unsafe { syscall(code as u64, 0, 0, 0, 0, 0, 0, SYS_EXIT) };
[INFO] [stdout]    |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]   --> src/syscalls.rs:37:15
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let ret = unsafe {
[INFO] [stdout]    |               ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/syscalls.rs:416:5
[INFO] [stdout]     |
[INFO] [stdout] 416 |     unsafe {
[INFO] [stdout]     |     ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/syscalls.rs:471:15
[INFO] [stdout]     |
[INFO] [stdout] 471 |     let ret = unsafe {
[INFO] [stdout]     |               ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 6.77s
[INFO] running `Command { std: "docker" "inspect" "bab9bf30946ac3dea3a09cf002f97fd543a33906541eee1f56b34db29b3fe90f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bab9bf30946ac3dea3a09cf002f97fd543a33906541eee1f56b34db29b3fe90f", kill_on_drop: false }`
[INFO] [stdout] bab9bf30946ac3dea3a09cf002f97fd543a33906541eee1f56b34db29b3fe90f