[INFO] fetching crate td_rthreadpool 0.1.4...
[INFO] checking td_rthreadpool-0.1.4 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate td_rthreadpool 0.1.4 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate td_rthreadpool 0.1.4 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate td_rthreadpool 0.1.4
[INFO] finished tweaking crates.io crate td_rthreadpool 0.1.4
[INFO] tweaked toml for crates.io crate td_rthreadpool 0.1.4 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 2 packages
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f3c64c05a4740d9614a6b67a360bc84a01d259674e85b42725f122f910cc2349
[INFO] running `Command { std: "docker" "start" "-a" "f3c64c05a4740d9614a6b67a360bc84a01d259674e85b42725f122f910cc2349", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f3c64c05a4740d9614a6b67a360bc84a01d259674e85b42725f122f910cc2349", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f3c64c05a4740d9614a6b67a360bc84a01d259674e85b42725f122f910cc2349", kill_on_drop: false }`
[INFO] [stdout] f3c64c05a4740d9614a6b67a360bc84a01d259674e85b42725f122f910cc2349
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 43e3cb65a4738baffcf642fa1918a4ea739d444ca79de0827a5f13a9c469c322
[INFO] running `Command { std: "docker" "start" "-a" "43e3cb65a4738baffcf642fa1918a4ea739d444ca79de0827a5f13a9c469c322", kill_on_drop: false }`
[INFO] [stderr]     Checking td_rthreadpool v0.1.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/mutex/unix.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     use libc;
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/lib.rs:1:1
[INFO] [stdout]    |
[INFO] [stdout] 1  | extern crate libc;
[INFO] [stdout]    | ------------------ the item `libc` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]    --> src/mutex/unix.rs:114:13
[INFO] [stdout]     |
[INFO] [stdout] 114 |         use libc;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]    ::: src/lib.rs:1:1
[INFO] [stdout]     |
[INFO] [stdout] 1   | extern crate libc;
[INFO] [stdout]     | ------------------ the item `libc` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]   --> src/mutex/unix.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |     use libc;
[INFO] [stdout]    |         ^^^^
[INFO] [stdout]    |
[INFO] [stdout]   ::: src/lib.rs:1:1
[INFO] [stdout]    |
[INFO] [stdout] 1  | extern crate libc;
[INFO] [stdout]    | ------------------ the item `libc` is already imported here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/mutex/remutex.rs:83:16
[INFO] [stdout]    |
[INFO] [stdout] 83 |             Ok(try!(ReentrantMutexGuard::new(&self)))
[INFO] [stdout]    |                ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `libc` is imported redundantly
[INFO] [stdout]    --> src/mutex/unix.rs:114:13
[INFO] [stdout]     |
[INFO] [stdout] 114 |         use libc;
[INFO] [stdout]     |             ^^^^
[INFO] [stdout]     |
[INFO] [stdout]    ::: src/lib.rs:1:1
[INFO] [stdout]     |
[INFO] [stdout] 1   | extern crate libc;
[INFO] [stdout]     | ------------------ the item `libc` is already imported here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/mutex/remutex.rs:83:16
[INFO] [stdout]    |
[INFO] [stdout] 83 |             Ok(try!(ReentrantMutexGuard::new(&self)))
[INFO] [stdout]    |                ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::mem::uninitialized`: use `mem::MaybeUninit` instead
[INFO] [stdout]   --> src/mutex/unix.rs:21:38
[INFO] [stdout]    |
[INFO] [stdout] 21 |         ReentrantMutex { inner: mem::uninitialized() }
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::mem::uninitialized`: use `mem::MaybeUninit` instead
[INFO] [stdout]   --> src/mutex/unix.rs:25:55
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let mut attr: ffi::pthread_mutexattr_t = mem::uninitialized();
[INFO] [stdout]    |                                                       ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:23:22
[INFO] [stdout]    |
[INFO] [stdout] 23 | type Thunk<'a> = Box<FnBox + Send + 'a>;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 23 | type Thunk<'a> = Box<dyn FnBox + Send + 'a>;
[INFO] [stdout]    |                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::mem::uninitialized`: use `mem::MaybeUninit` instead
[INFO] [stdout]   --> src/mutex/unix.rs:21:38
[INFO] [stdout]    |
[INFO] [stdout] 21 |         ReentrantMutex { inner: mem::uninitialized() }
[INFO] [stdout]    |                                      ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated function `std::mem::uninitialized`: use `mem::MaybeUninit` instead
[INFO] [stdout]   --> src/mutex/unix.rs:25:55
[INFO] [stdout]    |
[INFO] [stdout] 25 |         let mut attr: ffi::pthread_mutexattr_t = mem::uninitialized();
[INFO] [stdout]    |                                                       ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/lib.rs:23:22
[INFO] [stdout]    |
[INFO] [stdout] 23 | type Thunk<'a> = Box<FnBox + Send + 'a>;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 23 | type Thunk<'a> = Box<dyn FnBox + Send + 'a>;
[INFO] [stdout]    |                      +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/mutex/poison.rs:168:32
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn cause(&self) -> Option<&Error> {
[INFO] [stdout]     |                                ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/mutex/poison.rs:168:32
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn cause(&self) -> Option<&Error> {
[INFO] [stdout]     |                                ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is an object-safe trait, use `dyn`
[INFO] [stdout]     |
[INFO] [stdout] 168 |     fn cause(&self) -> Option<&dyn Error> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/mutex/poison.rs:156:14
[INFO] [stdout]     |
[INFO] [stdout] 156 |         self.description().fmt(f)
[INFO] [stdout]     |              ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/mutex/poison.rs:163:48
[INFO] [stdout]     |
[INFO] [stdout] 163 |             TryLockError::Poisoned(ref p) => p.description(),
[INFO] [stdout]     |                                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/mutex/poison.rs:156:14
[INFO] [stdout]     |
[INFO] [stdout] 156 |         self.description().fmt(f)
[INFO] [stdout]     |              ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated method `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]    --> src/mutex/poison.rs:163:48
[INFO] [stdout]     |
[INFO] [stdout] 163 |             TryLockError::Poisoned(ref p) => p.description(),
[INFO] [stdout]     |                                                ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the type `UnsafeCell<sys::ffi::os::pthread_mutex_t>` does not permit being left uninitialized
[INFO] [stdout]    --> src/mutex/unix.rs:21:33
[INFO] [stdout]     |
[INFO] [stdout] 21  |         ReentrantMutex { inner: mem::uninitialized() }
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |                                 |
[INFO] [stdout]     |                                 this code causes undefined behavior when executed
[INFO] [stdout]     |                                 help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
[INFO] [stdout]     |
[INFO] [stdout] note: integers must be initialized (in this struct field)
[INFO] [stdout]    --> src/mutex/unix.rs:129:13
[INFO] [stdout]     |
[INFO] [stdout] 129 |             __align: libc::c_longlong,
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     = note: `#[warn(invalid_value)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the type `sys::ffi::os::pthread_mutexattr_t` does not permit being left uninitialized
[INFO] [stdout]    --> src/mutex/unix.rs:25:50
[INFO] [stdout]     |
[INFO] [stdout] 25  |         let mut attr: ffi::pthread_mutexattr_t = mem::uninitialized();
[INFO] [stdout]     |                                                  ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |                                                  |
[INFO] [stdout]     |                                                  this code causes undefined behavior when executed
[INFO] [stdout]     |                                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
[INFO] [stdout]     |
[INFO] [stdout] note: integers must be initialized (in this struct field)
[INFO] [stdout]    --> src/mutex/unix.rs:134:13
[INFO] [stdout]     |
[INFO] [stdout] 134 |             __align: libc::c_longlong,
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the type `UnsafeCell<sys::ffi::os::pthread_mutex_t>` does not permit being left uninitialized
[INFO] [stdout]    --> src/mutex/unix.rs:21:33
[INFO] [stdout]     |
[INFO] [stdout] 21  |         ReentrantMutex { inner: mem::uninitialized() }
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |                                 |
[INFO] [stdout]     |                                 this code causes undefined behavior when executed
[INFO] [stdout]     |                                 help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
[INFO] [stdout]     |
[INFO] [stdout] note: integers must be initialized (in this struct field)
[INFO] [stdout]    --> src/mutex/unix.rs:129:13
[INFO] [stdout]     |
[INFO] [stdout] 129 |             __align: libc::c_longlong,
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     = note: `#[warn(invalid_value)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the type `sys::ffi::os::pthread_mutexattr_t` does not permit being left uninitialized
[INFO] [stdout]    --> src/mutex/unix.rs:25:50
[INFO] [stdout]     |
[INFO] [stdout] 25  |         let mut attr: ffi::pthread_mutexattr_t = mem::uninitialized();
[INFO] [stdout]     |                                                  ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |                                                  |
[INFO] [stdout]     |                                                  this code causes undefined behavior when executed
[INFO] [stdout]     |                                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
[INFO] [stdout]     |
[INFO] [stdout] note: integers must be initialized (in this struct field)
[INFO] [stdout]    --> src/mutex/unix.rs:134:13
[INFO] [stdout]     |
[INFO] [stdout] 134 |             __align: libc::c_longlong,
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 11 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `self`
[INFO] [stdout]  --> tests/test.rs:3:19
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::thread::{self, sleep};
[INFO] [stdout]   |                   ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> tests/test.rs:38:9
[INFO] [stdout]    |
[INFO] [stdout] 38 |     let mut pool = ThreadPool::new(TEST_TASKS);
[INFO] [stdout]    |         ----^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused arithmetic operation that must be used
[INFO] [stdout]   --> tests/test.rs:59:13
[INFO] [stdout]    |
[INFO] [stdout] 59 |             1 + 1;
[INFO] [stdout]    |             ^^^^^ the arithmetic operation produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 59 |             let _ = 1 + 1;
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.33s
[INFO] running `Command { std: "docker" "inspect" "43e3cb65a4738baffcf642fa1918a4ea739d444ca79de0827a5f13a9c469c322", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43e3cb65a4738baffcf642fa1918a4ea739d444ca79de0827a5f13a9c469c322", kill_on_drop: false }`
[INFO] [stdout] 43e3cb65a4738baffcf642fa1918a4ea739d444ca79de0827a5f13a9c469c322