[INFO] cloning repository https://github.com/kmf-lab/learn-lifetime [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kmf-lab/learn-lifetime" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkmf-lab%2Flearn-lifetime", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkmf-lab%2Flearn-lifetime'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] db4b08b678593772284e983ce718a513634d2fdb [INFO] checking kmf-lab/learn-lifetime against try#d534db0721b23cf977073bf4cd306dbf501e6b4d for pr-138499 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkmf-lab%2Flearn-lifetime" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'... [INFO] [stderr] done. [INFO] validating manifest of git repo https://github.com/kmf-lab/learn-lifetime on toolchain d534db0721b23cf977073bf4cd306dbf501e6b4d [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+d534db0721b23cf977073bf4cd306dbf501e6b4d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] started tweaking git repo https://github.com/kmf-lab/learn-lifetime [INFO] finished tweaking git repo https://github.com/kmf-lab/learn-lifetime [INFO] tweaked toml for git repo https://github.com/kmf-lab/learn-lifetime written to /workspace/builds/worker-6-tc2/source/Cargo.toml [INFO] crate git repo https://github.com/kmf-lab/learn-lifetime 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" "+d534db0721b23cf977073bf4cd306dbf501e6b4d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+d534db0721b23cf977073bf4cd306dbf501e6b4d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 51508b0cb11b88bb000d77e772644a72eee05670e8a72e2d0c1de44c288484c6 [INFO] running `Command { std: "docker" "start" "-a" "51508b0cb11b88bb000d77e772644a72eee05670e8a72e2d0c1de44c288484c6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "51508b0cb11b88bb000d77e772644a72eee05670e8a72e2d0c1de44c288484c6", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "51508b0cb11b88bb000d77e772644a72eee05670e8a72e2d0c1de44c288484c6", kill_on_drop: false }` [INFO] [stdout] 51508b0cb11b88bb000d77e772644a72eee05670e8a72e2d0c1de44c288484c6 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "-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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+d534db0721b23cf977073bf4cd306dbf501e6b4d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 31a95090739356100ec07537abe7254679cc96e0a07f2e5788831a940c2a4775 [INFO] running `Command { std: "docker" "start" "-a" "31a95090739356100ec07537abe7254679cc96e0a07f2e5788831a940c2a4775", kill_on_drop: false }` [INFO] [stderr] Compiling libc v0.2.155 [INFO] [stderr] Compiling zerocopy v0.8.0-alpha.6 [INFO] [stderr] Checking cfg-if v1.0.0 [INFO] [stderr] Checking ppv-lite86 v0.2.17 [INFO] [stderr] Checking getrandom v0.2.15 [INFO] [stderr] Checking rand_core v0.9.0-alpha.1 [INFO] [stderr] Checking rand_chacha v0.9.0-alpha.1 [INFO] [stderr] Checking rand v0.9.0-alpha.1 [INFO] [stderr] Checking learn-lifetimes v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: field `a` is never read [INFO] [stdout] --> src/lesson_2_struct.rs:35:13 [INFO] [stdout] | [INFO] [stdout] 34 | struct SimpleStruct { [INFO] [stdout] | ------------ field in this struct [INFO] [stdout] 35 | a: i32, [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `consume_return_a`, `process_a`, and `update_a` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:39:16 [INFO] [stdout] | [INFO] [stdout] 38 | impl SimpleStruct { [INFO] [stdout] | ----------------- methods in this implementation [INFO] [stdout] 39 | fn consume(self) {} [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] 40 | fn consume_return_a(self) -> i32 { [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 43 | fn process_a(self: &Self) -> &i32 { // Elided [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 46 | fn update_a(self: &mut Self, a: i32) -> &i32 { // Elided [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `b` is never read [INFO] [stdout] --> src/lesson_2_struct.rs:80:13 [INFO] [stdout] | [INFO] [stdout] 78 | struct UnifiedStruct<'a> { [INFO] [stdout] | ------------- field in this struct [INFO] [stdout] 79 | a: &'a String, // we typically give all refs the same lifetime [INFO] [stdout] 80 | b: &'a String [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `UnifiedStruct` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `consume_return_a`, `process_a`, `update_a`, and `update_b` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:86:16 [INFO] [stdout] | [INFO] [stdout] 85 | impl<'a> UnifiedStruct<'a> { [INFO] [stdout] | -------------------------- methods in this implementation [INFO] [stdout] 86 | fn consume(self) { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 89 | fn consume_return_a(self) -> &'a String { //consumed/dropped struct [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 92 | fn process_a(self: &Self) -> & String { //this ref is the same lifetime as struct [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 95 | fn update_a(self: & mut Self, a: &'a String) -> & String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 100 | fn update_b(self: &mut Self, b: &'a String) -> & String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `update_a`, and `update_b` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:159:16 [INFO] [stdout] | [INFO] [stdout] 158 | impl <'a,'b> SplitStruct<'a,'b> { [INFO] [stdout] | ------------------------------- methods in this implementation [INFO] [stdout] 159 | fn consume(self) { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 173 | fn update_a(self: &mut Self, a: &'a String) -> &String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 177 | fn update_b(self: &mut Self, b: &'b String) -> &String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `shortest_length_with_lifetime_subtyping` is never used [INFO] [stdout] --> src/lesson_3_function.rs:83:8 [INFO] [stdout] | [INFO] [stdout] 83 | fn shortest_length_with_lifetime_subtyping<'a,'b:'a>(x: &'a String, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing [INFO] [stdout] --> src/lesson_3_function.rs:51:13 [INFO] [stdout] | [INFO] [stdout] 51 | drop(_s_ref); //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] | ^^^^^------^ [INFO] [stdout] | | [INFO] [stdout] | argument has type `&str` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dropping_references)]` on by default [INFO] [stdout] help: use `let _ = ...` to ignore the expression or result [INFO] [stdout] | [INFO] [stdout] 51 - drop(_s_ref); //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] 51 + let _ = _s_ref; //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `a` is never read [INFO] [stdout] --> src/lesson_2_struct.rs:35:13 [INFO] [stdout] | [INFO] [stdout] 34 | struct SimpleStruct { [INFO] [stdout] | ------------ field in this struct [INFO] [stdout] 35 | a: i32, [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `consume_return_a`, `process_a`, and `update_a` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:39:16 [INFO] [stdout] | [INFO] [stdout] 38 | impl SimpleStruct { [INFO] [stdout] | ----------------- methods in this implementation [INFO] [stdout] 39 | fn consume(self) {} [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] 40 | fn consume_return_a(self) -> i32 { [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 43 | fn process_a(self: &Self) -> &i32 { // Elided [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 46 | fn update_a(self: &mut Self, a: i32) -> &i32 { // Elided [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: field `b` is never read [INFO] [stdout] --> src/lesson_2_struct.rs:80:13 [INFO] [stdout] | [INFO] [stdout] 78 | struct UnifiedStruct<'a> { [INFO] [stdout] | ------------- field in this struct [INFO] [stdout] 79 | a: &'a String, // we typically give all refs the same lifetime [INFO] [stdout] 80 | b: &'a String [INFO] [stdout] | ^ [INFO] [stdout] | [INFO] [stdout] = note: `UnifiedStruct` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `consume_return_a`, `process_a`, `update_a`, and `update_b` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:86:16 [INFO] [stdout] | [INFO] [stdout] 85 | impl<'a> UnifiedStruct<'a> { [INFO] [stdout] | -------------------------- methods in this implementation [INFO] [stdout] 86 | fn consume(self) { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 89 | fn consume_return_a(self) -> &'a String { //consumed/dropped struct [INFO] [stdout] | ^^^^^^^^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 92 | fn process_a(self: &Self) -> & String { //this ref is the same lifetime as struct [INFO] [stdout] | ^^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 95 | fn update_a(self: & mut Self, a: &'a String) -> & String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 100 | fn update_b(self: &mut Self, b: &'a String) -> & String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: methods `consume`, `update_a`, and `update_b` are never used [INFO] [stdout] --> src/lesson_2_struct.rs:159:16 [INFO] [stdout] | [INFO] [stdout] 158 | impl <'a,'b> SplitStruct<'a,'b> { [INFO] [stdout] | ------------------------------- methods in this implementation [INFO] [stdout] 159 | fn consume(self) { [INFO] [stdout] | ^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 173 | fn update_a(self: &mut Self, a: &'a String) -> &String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] ... [INFO] [stdout] 177 | fn update_b(self: &mut Self, b: &'b String) -> &String { [INFO] [stdout] | ^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: function `shortest_length_with_lifetime_subtyping` is never used [INFO] [stdout] --> src/lesson_3_function.rs:83:8 [INFO] [stdout] | [INFO] [stdout] 83 | fn shortest_length_with_lifetime_subtyping<'a,'b:'a>(x: &'a String, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: calls to `std::mem::drop` with a reference instead of an owned value does nothing [INFO] [stdout] --> src/lesson_3_function.rs:51:13 [INFO] [stdout] | [INFO] [stdout] 51 | drop(_s_ref); //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] | ^^^^^------^ [INFO] [stdout] | | [INFO] [stdout] | argument has type `&str` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dropping_references)]` on by default [INFO] [stdout] help: use `let _ = ...` to ignore the expression or result [INFO] [stdout] | [INFO] [stdout] 51 - drop(_s_ref); //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] 51 + let _ = _s_ref; //we must force _s_ref to live until now to protect the derived length [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stderr] Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.01s [INFO] running `Command { std: "docker" "inspect" "31a95090739356100ec07537abe7254679cc96e0a07f2e5788831a940c2a4775", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "31a95090739356100ec07537abe7254679cc96e0a07f2e5788831a940c2a4775", kill_on_drop: false }` [INFO] [stdout] 31a95090739356100ec07537abe7254679cc96e0a07f2e5788831a940c2a4775