[INFO] fetching crate icicle 0.1.1...
[INFO] checking icicle-0.1.1 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate icicle 0.1.1 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate icicle 0.1.1
[INFO] finished tweaking crates.io crate icicle 0.1.1
[INFO] tweaked toml for crates.io crate icicle 0.1.1 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate icicle 0.1.1 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate icicle 0.1.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b8f446a53feaf3e36dde04af7aad501ec039073aa59bd0c82e48ceebc1bfcedd
[INFO] running `Command { std: "docker" "start" "-a" "b8f446a53feaf3e36dde04af7aad501ec039073aa59bd0c82e48ceebc1bfcedd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b8f446a53feaf3e36dde04af7aad501ec039073aa59bd0c82e48ceebc1bfcedd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8f446a53feaf3e36dde04af7aad501ec039073aa59bd0c82e48ceebc1bfcedd", kill_on_drop: false }`
[INFO] [stdout] b8f446a53feaf3e36dde04af7aad501ec039073aa59bd0c82e48ceebc1bfcedd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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 -Dunmustuse_in_always_ok" "-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fdc6a9eca4d816609f5d2bf06a633336c62f6e489eb7e7b3b09b9040037cd68c
[INFO] running `Command { std: "docker" "start" "-a" "fdc6a9eca4d816609f5d2bf06a633336c62f6e489eb7e7b3b09b9040037cd68c", kill_on_drop: false }`
[INFO] [stderr]     Checking icicle v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]    --> src/lib.rs:310:27
[INFO] [stdout]     |
[INFO] [stdout] 310 |         let mut builder = String::from_str(prefix).unwrap();
[INFO] [stdout]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:206:17
[INFO] [stdout]     |
[INFO] [stdout] 206 |     pub fn iter(&self) -> Iter<String> {
[INFO] [stdout]     |                 ^^^^^     ^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 206 |     pub fn iter(&self) -> Iter<'_, String> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:211:21
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn iter_opt(&self) -> MapIter<String, String> {
[INFO] [stdout]     |                     ^^^^^     ^^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn iter_opt(&self) -> MapIter<'_, String, String> {
[INFO] [stdout]     |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:216:21
[INFO] [stdout]     |
[INFO] [stdout] 216 |     pub fn iter_mut(&mut self) -> IterMut<String> {
[INFO] [stdout]     |                     ^^^^^^^^^     ^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 216 |     pub fn iter_mut(&mut self) -> IterMut<'_, String> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:221:25
[INFO] [stdout]     |
[INFO] [stdout] 221 |     pub fn iter_mut_opt(&mut self) -> MapIterMut<String, String> {
[INFO] [stdout]     |                         ^^^^^^^^^     ^^^^^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 221 |     pub fn iter_mut_opt(&mut self) -> MapIterMut<'_, String, String> {
[INFO] [stdout]     |                                                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `icicle` (lib) due to 1 previous error; 4 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]    --> src/lib.rs:310:27
[INFO] [stdout]     |
[INFO] [stdout] 310 |         let mut builder = String::from_str(prefix).unwrap();
[INFO] [stdout]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:206:17
[INFO] [stdout]     |
[INFO] [stdout] 206 |     pub fn iter(&self) -> Iter<String> {
[INFO] [stdout]     |                 ^^^^^     ^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]     = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 206 |     pub fn iter(&self) -> Iter<'_, String> {
[INFO] [stdout]     |                                +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:211:21
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn iter_opt(&self) -> MapIter<String, String> {
[INFO] [stdout]     |                     ^^^^^     ^^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 211 |     pub fn iter_opt(&self) -> MapIter<'_, String, String> {
[INFO] [stdout]     |                                       +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:216:21
[INFO] [stdout]     |
[INFO] [stdout] 216 |     pub fn iter_mut(&mut self) -> IterMut<String> {
[INFO] [stdout]     |                     ^^^^^^^^^     ^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 216 |     pub fn iter_mut(&mut self) -> IterMut<'_, String> {
[INFO] [stdout]     |                                           +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]    --> src/args.rs:221:25
[INFO] [stdout]     |
[INFO] [stdout] 221 |     pub fn iter_mut_opt(&mut self) -> MapIterMut<String, String> {
[INFO] [stdout]     |                         ^^^^^^^^^     ^^^^^^^^^^^^^^^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]     |                         |
[INFO] [stdout]     |                         the lifetime is elided here
[INFO] [stdout]     |
[INFO] [stdout]     = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]     |
[INFO] [stdout] 221 |     pub fn iter_mut_opt(&mut self) -> MapIterMut<'_, String, String> {
[INFO] [stdout]     |                                                  +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `icicle` (lib test) due to 1 previous error; 4 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "fdc6a9eca4d816609f5d2bf06a633336c62f6e489eb7e7b3b09b9040037cd68c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fdc6a9eca4d816609f5d2bf06a633336c62f6e489eb7e7b3b09b9040037cd68c", kill_on_drop: false }`
[INFO] [stdout] fdc6a9eca4d816609f5d2bf06a633336c62f6e489eb7e7b3b09b9040037cd68c