[INFO] updating cached repository https://github.com/pjungwir/rust-thread-read-to-string
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/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] 45c3aacc5ff0bd0df32aff67a1d240948f047874
[INFO] checking pjungwir/rust-thread-read-to-string against master#4ff32c07da9d97e6dc315a4a5c9ffbb797cb27bb for pr-64672
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpjungwir%2Frust-thread-read-to-string" "work/builds/worker-7/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/pjungwir/rust-thread-read-to-string on toolchain 4ff32c07da9d97e6dc315a4a5c9ffbb797cb27bb
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+4ff32c07da9d97e6dc315a4a5c9ffbb797cb27bb" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/pjungwir/rust-thread-read-to-string
[INFO] finished tweaking git repo https://github.com/pjungwir/rust-thread-read-to-string
[INFO] tweaked toml for git repo https://github.com/pjungwir/rust-thread-read-to-string written to work/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/pjungwir/rust-thread-read-to-string already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+4ff32c07da9d97e6dc315a4a5c9ffbb797cb27bb" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-7/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "+4ff32c07da9d97e6dc315a4a5c9ffbb797cb27bb" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] c1cc14eeddd4d3ce77dc87dc474945b31d85bc829bc3e86d7a7e725d24111239
[INFO] running `"docker" "start" "-a" "c1cc14eeddd4d3ce77dc87dc474945b31d85bc829bc3e86d7a7e725d24111239"`
[INFO] [stderr]    Compiling semver v0.1.20
[INFO] [stderr]     Checking matches v0.1.4
[INFO] [stderr]     Checking unicode-normalization v0.1.4
[INFO] [stderr]     Checking libc v0.2.21
[INFO] [stderr]     Checking log v0.3.7
[INFO] [stderr]     Checking rustc-serialize v0.3.22
[INFO] [stderr]     Checking httparse v1.2.1
[INFO] [stderr]     Checking unicode-bidi v0.2.5
[INFO] [stderr]     Checking mime v0.2.2
[INFO] [stderr]    Compiling rustc_version v0.1.7
[INFO] [stderr]     Checking time v0.1.36
[INFO] [stderr]     Checking num_cpus v1.3.0
[INFO] [stderr]    Compiling unicase v1.4.0
[INFO] [stderr]    Compiling hyper v0.10.5
[INFO] [stderr]     Checking idna v0.1.0
[INFO] [stderr]     Checking url v1.4.0
[INFO] [stderr] warning[E0713]: borrow may still be in use when destructor runs
[INFO] [stderr]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/url-1.4.0/src/form_urlencoded.rs:246:40
[INFO] [stderr]     |
[INFO] [stderr] 244 | impl<'a> Target for ::UrlQuery<'a> {
[INFO] [stderr]     |      -- lifetime `'a` defined here
[INFO] [stderr] 245 |     fn as_mut_string(&mut self) -> &mut String { &mut self.url.serialization }
[INFO] [stderr] 246 |     fn finish(self) -> &'a mut ::Url { self.url }
[INFO] [stderr]     |                                        ^^^^^^^^ - here, drop of `self` needs exclusive access to `*self.url`, because the type `UrlQuery<'_>` implements the `Drop` trait
[INFO] [stderr]     |                                        |
[INFO] [stderr]     |                                        returning this value requires that `*self.url` is borrowed for `'a`
[INFO] [stderr]     |
[INFO] [stderr]     = warning: this error has been downgraded to a warning for backwards compatibility with previous releases
[INFO] [stderr]     = warning: this represents potential undefined behavior in your code and this warning will become a hard error in the future
[INFO] [stderr]     = note: for more information, try `rustc --explain E0729`
[INFO] [stderr] 
[INFO] [stderr]     Checking thread-read-to-string v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `Request`
[INFO] [stderr]  --> src/main.rs:9:21
[INFO] [stderr]   |
[INFO] [stderr] 9 | use hyper::client::{Request, Response};
[INFO] [stderr]   |                     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Request`
[INFO] [stderr]  --> src/main.rs:9:21
[INFO] [stderr]   |
[INFO] [stderr] 9 | use hyper::client::{Request, Response};
[INFO] [stderr]   |                     ^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]   --> src/main.rs:27:7
[INFO] [stderr]    |
[INFO] [stderr] 27 |   let t = thread::spawn(move || {
[INFO] [stderr]    |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]   --> src/main.rs:73:7
[INFO] [stderr]    |
[INFO] [stderr] 73 |   let t = thread::spawn(move || {
[INFO] [stderr]    |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:108:7
[INFO] [stderr]     |
[INFO] [stderr] 108 |   let t = thread::spawn(move || {
[INFO] [stderr]     |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:141:7
[INFO] [stderr]     |
[INFO] [stderr] 141 |   let t = thread::spawn(move || {
[INFO] [stderr]     |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:185:8
[INFO] [stderr]     |
[INFO] [stderr] 185 |   let (status_code, buf) = get_url_with_timeout_3("http://example.com/").unwrap();
[INFO] [stderr]     |        ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:188:8
[INFO] [stderr]     |
[INFO] [stderr] 188 |   let (status_code, buf) = get_url_with_timeout_4("http://example.com/").unwrap();
[INFO] [stderr]     |        ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:193:7
[INFO] [stderr]     |
[INFO] [stderr] 193 |   let status_code = get_url_with_timeout_5("http://example.com/", &shbuf).unwrap();
[INFO] [stderr]     |       ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:19:7
[INFO] [stderr]    |
[INFO] [stderr] 19 |   let mut c = Client::new();
[INFO] [stderr]    |       ----^
[INFO] [stderr]    |       |
[INFO] [stderr]    |       help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:20:7
[INFO] [stderr]    |
[INFO] [stderr] 20 |   let mut req = c.get(url);
[INFO] [stderr]    |       ----^^^
[INFO] [stderr]    |       |
[INFO] [stderr]    |       help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:74:9
[INFO] [stderr]    |
[INFO] [stderr] 74 |     let mut c = Client::new();
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:75:9
[INFO] [stderr]    |
[INFO] [stderr] 75 |     let mut req = c.get(&url);
[INFO] [stderr]    |         ----^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:76:9
[INFO] [stderr]    |
[INFO] [stderr] 76 |     let mut ret = match req.send() {
[INFO] [stderr]    |         ----^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:109:9
[INFO] [stderr]     |
[INFO] [stderr] 109 |     let mut c = Client::new();
[INFO] [stderr]     |         ----^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:110:9
[INFO] [stderr]     |
[INFO] [stderr] 110 |     let mut req = c.get(&url);
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:111:9
[INFO] [stderr]     |
[INFO] [stderr] 111 |     let mut ret = match req.send() {
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:142:9
[INFO] [stderr]     |
[INFO] [stderr] 142 |     let mut c = Client::new();
[INFO] [stderr]     |         ----^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:143:9
[INFO] [stderr]     |
[INFO] [stderr] 143 |     let mut req = c.get(&url);
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:144:9
[INFO] [stderr]     |
[INFO] [stderr] 144 |     let mut ret = match req.send() {
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:137:38
[INFO] [stderr]     |
[INFO] [stderr] 137 | fn get_url_with_timeout_5(url: &str, mut shbuf: &Arc<Mutex<String>>) -> Result<u16, MyAppError> {
[INFO] [stderr]     |                                      ----^^^^^
[INFO] [stderr]     |                                      |
[INFO] [stderr]     |                                      help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]   --> src/main.rs:27:7
[INFO] [stderr]    |
[INFO] [stderr] 27 |   let t = thread::spawn(move || {
[INFO] [stderr]    |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]   --> src/main.rs:73:7
[INFO] [stderr]    |
[INFO] [stderr] 73 |   let t = thread::spawn(move || {
[INFO] [stderr]    |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:108:7
[INFO] [stderr]     |
[INFO] [stderr] 108 |   let t = thread::spawn(move || {
[INFO] [stderr]     |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `t`
[INFO] [stderr]    --> src/main.rs:141:7
[INFO] [stderr]     |
[INFO] [stderr] 141 |   let t = thread::spawn(move || {
[INFO] [stderr]     |       ^ help: consider prefixing with an underscore: `_t`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:185:8
[INFO] [stderr]     |
[INFO] [stderr] 185 |   let (status_code, buf) = get_url_with_timeout_3("http://example.com/").unwrap();
[INFO] [stderr]     |        ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:188:8
[INFO] [stderr]     |
[INFO] [stderr] 188 |   let (status_code, buf) = get_url_with_timeout_4("http://example.com/").unwrap();
[INFO] [stderr]     |        ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `status_code`
[INFO] [stderr]    --> src/main.rs:193:7
[INFO] [stderr]     |
[INFO] [stderr] 193 |   let status_code = get_url_with_timeout_5("http://example.com/", &shbuf).unwrap();
[INFO] [stderr]     |       ^^^^^^^^^^^ help: consider prefixing with an underscore: `_status_code`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:19:7
[INFO] [stderr]    |
[INFO] [stderr] 19 |   let mut c = Client::new();
[INFO] [stderr]    |       ----^
[INFO] [stderr]    |       |
[INFO] [stderr]    |       help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:20:7
[INFO] [stderr]    |
[INFO] [stderr] 20 |   let mut req = c.get(url);
[INFO] [stderr]    |       ----^^^
[INFO] [stderr]    |       |
[INFO] [stderr]    |       help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:74:9
[INFO] [stderr]    |
[INFO] [stderr] 74 |     let mut c = Client::new();
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:75:9
[INFO] [stderr]    |
[INFO] [stderr] 75 |     let mut req = c.get(&url);
[INFO] [stderr]    |         ----^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:76:9
[INFO] [stderr]    |
[INFO] [stderr] 76 |     let mut ret = match req.send() {
[INFO] [stderr]    |         ----^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:109:9
[INFO] [stderr]     |
[INFO] [stderr] 109 |     let mut c = Client::new();
[INFO] [stderr]     |         ----^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:110:9
[INFO] [stderr]     |
[INFO] [stderr] 110 |     let mut req = c.get(&url);
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:111:9
[INFO] [stderr]     |
[INFO] [stderr] 111 |     let mut ret = match req.send() {
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:142:9
[INFO] [stderr]     |
[INFO] [stderr] 142 |     let mut c = Client::new();
[INFO] [stderr]     |         ----^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:143:9
[INFO] [stderr]     |
[INFO] [stderr] 143 |     let mut req = c.get(&url);
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:144:9
[INFO] [stderr]     |
[INFO] [stderr] 144 |     let mut ret = match req.send() {
[INFO] [stderr]     |         ----^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:137:38
[INFO] [stderr]     |
[INFO] [stderr] 137 | fn get_url_with_timeout_5(url: &str, mut shbuf: &Arc<Mutex<String>>) -> Result<u16, MyAppError> {
[INFO] [stderr]     |                                      ----^^^^^
[INFO] [stderr]     |                                      |
[INFO] [stderr]     |                                      help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.72s
[INFO] running `"docker" "inspect" "c1cc14eeddd4d3ce77dc87dc474945b31d85bc829bc3e86d7a7e725d24111239"`
[INFO] running `"docker" "rm" "-f" "c1cc14eeddd4d3ce77dc87dc474945b31d85bc829bc3e86d7a7e725d24111239"`
[INFO] [stdout] c1cc14eeddd4d3ce77dc87dc474945b31d85bc829bc3e86d7a7e725d24111239