[INFO] fetching crate template_cp 0.1.3...
[INFO] testing template_cp-0.1.3 against try#db823df02fd0c2cf67b43025ac3fef3f2d743245 for pr-150681
[INFO] extracting crate template_cp 0.1.3 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate template_cp 0.1.3
[INFO] finished tweaking crates.io crate template_cp 0.1.3
[INFO] tweaked toml for crates.io crate template_cp 0.1.3 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate template_cp 0.1.3 on toolchain db823df02fd0c2cf67b43025ac3fef3f2d743245
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate template_cp 0.1.3 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" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] af85f785e13f3ea71d0b358d48e88f685d70c27b504c695f3a45ca9dccc76e05
[INFO] running `Command { std: "docker" "start" "-a" "af85f785e13f3ea71d0b358d48e88f685d70c27b504c695f3a45ca9dccc76e05", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af85f785e13f3ea71d0b358d48e88f685d70c27b504c695f3a45ca9dccc76e05", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af85f785e13f3ea71d0b358d48e88f685d70c27b504c695f3a45ca9dccc76e05", kill_on_drop: false }`
[INFO] [stdout] af85f785e13f3ea71d0b358d48e88f685d70c27b504c695f3a45ca9dccc76e05
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ca545becb7efb59af350c95c8cd9aa5f3891c0ce9e31b50fbeca9f0324406bf3
[INFO] running `Command { std: "docker" "start" "-a" "ca545becb7efb59af350c95c8cd9aa5f3891c0ce9e31b50fbeca9f0324406bf3", kill_on_drop: false }`
[INFO] [stderr]    Compiling template_cp v0.1.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.57s
[INFO] running `Command { std: "docker" "inspect" "ca545becb7efb59af350c95c8cd9aa5f3891c0ce9e31b50fbeca9f0324406bf3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca545becb7efb59af350c95c8cd9aa5f3891c0ce9e31b50fbeca9f0324406bf3", kill_on_drop: false }`
[INFO] [stdout] ca545becb7efb59af350c95c8cd9aa5f3891c0ce9e31b50fbeca9f0324406bf3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 55bb29963a667fd28b49a8b9e333020d2a397aeaa31583e10532b6c606e246b6
[INFO] running `Command { std: "docker" "start" "-a" "55bb29963a667fd28b49a8b9e333020d2a397aeaa31583e10532b6c606e246b6", kill_on_drop: false }`
[INFO] [stderr]    Compiling template_cp v0.1.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.73s
[INFO] running `Command { std: "docker" "inspect" "55bb29963a667fd28b49a8b9e333020d2a397aeaa31583e10532b6c606e246b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "55bb29963a667fd28b49a8b9e333020d2a397aeaa31583e10532b6c606e246b6", kill_on_drop: false }`
[INFO] [stdout] 55bb29963a667fd28b49a8b9e333020d2a397aeaa31583e10532b6c606e246b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:845e597a41426bbf2703be69acdb67d10b6de511142d05cba7bbe119c898b2c7" "/opt/rustwide/cargo-home/bin/cargo" "+db823df02fd0c2cf67b43025ac3fef3f2d743245" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] e43dc0a2ca18b9d36a882931aca9d13694d777eae46ff01ccce44c2e7951e355
[INFO] running `Command { std: "docker" "start" "-a" "e43dc0a2ca18b9d36a882931aca9d13694d777eae46ff01ccce44c2e7951e355", kill_on_drop: false }`
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.03s
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/template_cp-5980ceef0e576eba)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/new-bin.rs (/opt/rustwide/target/debug/deps/new_bin-3542e93a5169ebc4)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/rust-bin.rs (/opt/rustwide/target/debug/deps/rust_bin-a6235d5606223352)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/template.rs (/opt/rustwide/target/debug/deps/template-f3e8df6b2ac1c963)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/template_local.rs (/opt/rustwide/target/debug/deps/template_local-0c1d3bfaacf78275)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]      Running unittests src/bin/template_safe.rs (/opt/rustwide/target/debug/deps/template_safe-a2b99d6c4d84c267)
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests template_cp
[INFO] [stdout] 
[INFO] [stdout] running 8 tests
[INFO] [stdout] test src/iom.rs - iom::Scanner<R>::tok (line 72) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::Scanner (line 8) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::Scanner<R>::new (line 49) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::file_writer (line 116) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::Scanner<R>::tok (line 78) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::Scanner (line 24) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::Scanner<R>::new (line 54) ... FAILED
[INFO] [stdout] test src/iom.rs - iom::file_reader (line 103) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- src/iom.rs - iom::Scanner<R>::tok (line 72) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]   --> src/iom.rs:73:5
[INFO] [stdout]    |
[INFO] [stdout] 73 | use cp_template::Scanner;
[INFO] [stdout]    |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]    |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 73 - use cp_template::Scanner;
[INFO] [stdout] 73 + use template_cp::Scanner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::Scanner (line 8) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]  --> src/iom.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use cp_template::Scanner;
[INFO] [stdout]   |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]   |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]   |
[INFO] [stdout] 9 - use cp_template::Scanner;
[INFO] [stdout] 9 + use template_cp::Scanner;
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::Scanner<R>::new (line 49) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]   --> src/iom.rs:50:5
[INFO] [stdout]    |
[INFO] [stdout] 50 | use cp_template::Scanner;
[INFO] [stdout]    |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]    |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 50 - use cp_template::Scanner;
[INFO] [stdout] 50 + use template_cp::Scanner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::file_writer (line 116) stdout ----
[INFO] [stdout] error[E0599]: cannot write into `BufWriter<File>`
[INFO] [stdout]    --> src/iom.rs:122:10
[INFO] [stdout]     |
[INFO] [stdout] 122 | writeln!(out, "{}", n).ok();
[INFO] [stdout]     |          ^^^
[INFO] [stdout]     |
[INFO] [stdout]    --> /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/io/mod.rs:1990:7
[INFO] [stdout]     |
[INFO] [stdout]     = note: the method is available for `BufWriter<File>` here
[INFO] [stdout] note: must implement `io::Write`, `fmt::Write`, or have a `write_fmt` method
[INFO] [stdout]    --> src/iom.rs:122:10
[INFO] [stdout]     |
[INFO] [stdout] 122 | writeln!(out, "{}", n).ok();
[INFO] [stdout]     |          ^^^
[INFO] [stdout]     = help: items from traits can only be used if the trait is in scope
[INFO] [stdout] help: trait `Write` which provides `write_fmt` is implemented but not in scope; perhaps you want to import it
[INFO] [stdout]     |
[INFO] [stdout] 115 + use std::io::Write;
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::Scanner<R>::tok (line 78) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]   --> src/iom.rs:79:5
[INFO] [stdout]    |
[INFO] [stdout] 79 | use cp_template::Scanner;
[INFO] [stdout]    |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]    |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 79 - use cp_template::Scanner;
[INFO] [stdout] 79 + use template_cp::Scanner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::Scanner (line 24) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]   --> src/iom.rs:25:5
[INFO] [stdout]    |
[INFO] [stdout] 25 | use cp_template::Scanner;
[INFO] [stdout]    |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]    |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 25 - use cp_template::Scanner;
[INFO] [stdout] 25 + use template_cp::Scanner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error[E0425]: cannot find function `read_file` in this scope
[INFO] [stdout]   --> src/iom.rs:29:20
[INFO] [stdout]    |
[INFO] [stdout] 29 |     let mut scan = read_file("in.txt").unwrap();
[INFO] [stdout]    |                    ^^^^^^^^^ not found in this scope
[INFO] [stdout] 
[INFO] [stdout] error[E0425]: cannot find function `writer_file` in this scope
[INFO] [stdout]   --> src/iom.rs:30:19
[INFO] [stdout]    |
[INFO] [stdout] 30 |     let mut out = writer_file("out.txt").unwrap();
[INFO] [stdout]    |                   ^^^^^^^^^^^ not found in this scope
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0425, E0432.
[INFO] [stdout] For more information about an error, try `rustc --explain E0425`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::Scanner<R>::new (line 54) stdout ----
[INFO] [stdout] error[E0432]: unresolved import `cp_template`
[INFO] [stdout]   --> src/iom.rs:55:5
[INFO] [stdout]    |
[INFO] [stdout] 55 | use cp_template::Scanner;
[INFO] [stdout]    |     ^^^^^^^^^^^ use of unresolved module or unlinked crate `cp_template`
[INFO] [stdout]    |
[INFO] [stdout] help: there is a crate or module with a similar name
[INFO] [stdout]    |
[INFO] [stdout] 55 - use cp_template::Scanner;
[INFO] [stdout] 55 + use template_cp::Scanner;
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error[E0425]: cannot find value `filename` in this scope
[INFO] [stdout]   --> src/iom.rs:57:32
[INFO] [stdout]    |
[INFO] [stdout] 57 | let file = std::fs::File::open(filename)?;
[INFO] [stdout]    |                                ^^^^^^^^ not found in this scope
[INFO] [stdout] 
[INFO] [stdout] error[E0433]: failed to resolve: use of unresolved module or unlinked crate `io`
[INFO] [stdout]   --> src/iom.rs:58:14
[INFO] [stdout]    |
[INFO] [stdout] 58 | Scanner::new(io::BufReader::new(file))
[INFO] [stdout]    |              ^^ use of unresolved module or unlinked crate `io`
[INFO] [stdout]    |
[INFO] [stdout]    = help: if you wanted to use a crate named `io`, use `cargo add io` to add it to your `Cargo.toml`
[INFO] [stdout] help: consider importing this struct
[INFO] [stdout]    |
[INFO] [stdout] 54 + use std::io::BufReader;
[INFO] [stdout]    |
[INFO] [stdout] help: if you import `BufReader`, refer to it directly
[INFO] [stdout]    |
[INFO] [stdout] 58 - Scanner::new(io::BufReader::new(file))
[INFO] [stdout] 58 + Scanner::new(BufReader::new(file))
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/iom.rs:57:41
[INFO] [stdout]    |
[INFO] [stdout] 54 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_iom_rs_54_0() {
[INFO] [stdout]    |                                      ---------------------------------- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout] ...
[INFO] [stdout] 57 | let file = std::fs::File::open(filename)?;
[INFO] [stdout]    |                                         ^ cannot use the `?` operator in a function that returns `()`
[INFO] [stdout]    |
[INFO] [stdout] help: consider adding return type
[INFO] [stdout]    |
[INFO] [stdout] 54 | fn main() { #[allow(non_snake_case)] fn _doctest_main_src_iom_rs_54_0() -> Result<(), Box<dyn std::error::Error>> {
[INFO] [stdout]    |                                                                         +++++++++++++++++++++++++++++++++++++++++
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0277, E0425, E0432, E0433.
[INFO] [stdout] For more information about an error, try `rustc --explain E0277`.
[INFO] [stdout] Couldn't compile the test.
[INFO] [stdout] ---- src/iom.rs - iom::file_reader (line 103) stdout ----
[INFO] [stdout] Test executable failed (exit status: 101).
[INFO] [stdout] 
[INFO] [stdout] stderr:
[INFO] [stdout] 
[INFO] [stdout] thread 'main' (79) panicked at src/iom.rs:7:38:
[INFO] [stdout] called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x573eaa46f732 - std[3f03f8b59f91bef1]::backtrace_rs::backtrace::libunwind::trace
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stdout]    1:     0x573eaa46f732 - std[3f03f8b59f91bef1]::backtrace_rs::backtrace::trace_unsynchronized::<std[3f03f8b59f91bef1]::sys::backtrace::_print_fmt::{closure#1}>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stdout]    2:     0x573eaa46f732 - std[3f03f8b59f91bef1]::sys::backtrace::_print_fmt
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/sys/backtrace.rs:74:9
[INFO] [stdout]    3:     0x573eaa46f732 - <<std[3f03f8b59f91bef1]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[585f66e14d78f9ba]::fmt::Display>::fmt
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/sys/backtrace.rs:44:26
[INFO] [stdout]    4:     0x573eaa4807ea - <core[585f66e14d78f9ba]::fmt::rt::Argument>::fmt
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/core/src/fmt/rt.rs:152:76
[INFO] [stdout]    5:     0x573eaa4807ea - core[585f66e14d78f9ba]::fmt::write
[INFO] [stdout]    6:     0x573eaa473676 - std[3f03f8b59f91bef1]::io::default_write_fmt::<std[3f03f8b59f91bef1]::sys::stdio::unix::Stderr>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/io/mod.rs:639:11
[INFO] [stdout]    7:     0x573eaa473676 - <std[3f03f8b59f91bef1]::sys::stdio::unix::Stderr as std[3f03f8b59f91bef1]::io::Write>::write_fmt
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/io/mod.rs:1994:13
[INFO] [stdout]    8:     0x573eaa45aa1f - <std[3f03f8b59f91bef1]::sys::backtrace::BacktraceLock>::print
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/sys/backtrace.rs:47:9
[INFO] [stdout]    9:     0x573eaa45aa1f - std[3f03f8b59f91bef1]::panicking::default_hook::{closure#0}
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:292:27
[INFO] [stdout]   10:     0x573eaa46bc31 - std[3f03f8b59f91bef1]::panicking::default_hook
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:319:9
[INFO] [stdout]   11:     0x573eaa46bdeb - std[3f03f8b59f91bef1]::panicking::panic_with_hook
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:825:13
[INFO] [stdout]   12:     0x573eaa45aad8 - std[3f03f8b59f91bef1]::panicking::panic_handler::{closure#0}
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:698:13
[INFO] [stdout]   13:     0x573eaa44fff9 - std[3f03f8b59f91bef1]::sys::backtrace::__rust_end_short_backtrace::<std[3f03f8b59f91bef1]::panicking::panic_handler::{closure#0}, !>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/sys/backtrace.rs:182:18
[INFO] [stdout]   14:     0x573eaa45b2fd - __rustc[caa99d26c7bae192]::rust_begin_unwind
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:689:5
[INFO] [stdout]   15:     0x573eaa480e9c - core[585f66e14d78f9ba]::panicking::panic_fmt
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/core/src/panicking.rs:80:14
[INFO] [stdout]   16:     0x573eaa480c72 - core[585f66e14d78f9ba]::result::unwrap_failed
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/core/src/result.rs:1867:5
[INFO] [stdout]   17:     0x573eaa441d88 - rust_out[183646e59c86b0c5]::main::_doctest_main_src_iom_rs_103_0
[INFO] [stdout]   18:     0x573eaa441066 - rust_out[183646e59c86b0c5]::main
[INFO] [stdout]   19:     0x573eaa442833 - <fn() as core[585f66e14d78f9ba]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]   20:     0x573eaa440c26 - std[3f03f8b59f91bef1]::sys::backtrace::__rust_begin_short_backtrace::<fn(), ()>
[INFO] [stdout]   21:     0x573eaa440fb9 - std[3f03f8b59f91bef1]::rt::lang_start::<()>::{closure#0}
[INFO] [stdout]   22:     0x573eaa46b226 - <&dyn core[585f66e14d78f9ba]::ops::function::Fn<(), Output = i32> + core[585f66e14d78f9ba]::marker::Sync + core[585f66e14d78f9ba]::panic::unwind_safe::RefUnwindSafe as core[585f66e14d78f9ba]::ops::function::FnOnce<()>>::call_once
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/core/src/ops/function.rs:287:21
[INFO] [stdout]   23:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panicking::catch_unwind::do_call::<&dyn core[585f66e14d78f9ba]::ops::function::Fn<(), Output = i32> + core[585f66e14d78f9ba]::marker::Sync + core[585f66e14d78f9ba]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:581:40
[INFO] [stdout]   24:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panicking::catch_unwind::<i32, &dyn core[585f66e14d78f9ba]::ops::function::Fn<(), Output = i32> + core[585f66e14d78f9ba]::marker::Sync + core[585f66e14d78f9ba]::panic::unwind_safe::RefUnwindSafe>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:544:19
[INFO] [stdout]   25:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panic::catch_unwind::<&dyn core[585f66e14d78f9ba]::ops::function::Fn<(), Output = i32> + core[585f66e14d78f9ba]::marker::Sync + core[585f66e14d78f9ba]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panic.rs:359:14
[INFO] [stdout]   26:     0x573eaa46b226 - std[3f03f8b59f91bef1]::rt::lang_start_internal::{closure#0}
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/rt.rs:175:24
[INFO] [stdout]   27:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panicking::catch_unwind::do_call::<std[3f03f8b59f91bef1]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:581:40
[INFO] [stdout]   28:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panicking::catch_unwind::<isize, std[3f03f8b59f91bef1]::rt::lang_start_internal::{closure#0}>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panicking.rs:544:19
[INFO] [stdout]   29:     0x573eaa46b226 - std[3f03f8b59f91bef1]::panic::catch_unwind::<std[3f03f8b59f91bef1]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/panic.rs:359:14
[INFO] [stdout]   30:     0x573eaa46b226 - std[3f03f8b59f91bef1]::rt::lang_start_internal
[INFO] [stdout]                                at /rustc/db823df02fd0c2cf67b43025ac3fef3f2d743245/library/std/src/rt.rs:171:5
[INFO] [stdout]   31:     0x573eaa440b81 - std[3f03f8b59f91bef1]::rt::lang_start::<()>
[INFO] [stdout]   32:     0x573eaa442945 - main
[INFO] [stdout]   33:     0x7e87180821ca - <unknown>
[INFO] [stdout]   34:     0x7e871808228b - __libc_start_main
[INFO] [stdout]   35:     0x573eaa440405 - _start
[INFO] [stdout]   36:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     src/iom.rs - iom::Scanner (line 24)
[INFO] [stdout]     src/iom.rs - iom::Scanner (line 8)
[INFO] [stdout]     src/iom.rs - iom::Scanner<R>::new (line 49)
[INFO] [stdout]     src/iom.rs - iom::Scanner<R>::new (line 54)
[INFO] [stdout]     src/iom.rs - iom::Scanner<R>::tok (line 72)
[INFO] [stdout]     src/iom.rs - iom::Scanner<R>::tok (line 78)
[INFO] [stdout]     src/iom.rs - iom::file_reader (line 103)
[INFO] [stdout]     src/iom.rs - iom::file_writer (line 116)
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 0 passed; 8 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.49s
[INFO] [stdout] 
[INFO] [stderr] error: doctest failed, to rerun pass `--doc`
[INFO] running `Command { std: "docker" "inspect" "e43dc0a2ca18b9d36a882931aca9d13694d777eae46ff01ccce44c2e7951e355", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e43dc0a2ca18b9d36a882931aca9d13694d777eae46ff01ccce44c2e7951e355", kill_on_drop: false }`
[INFO] [stdout] e43dc0a2ca18b9d36a882931aca9d13694d777eae46ff01ccce44c2e7951e355
