[INFO] cloning repository https://github.com/Nandem/Rust_learning
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Nandem/Rust_learning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNandem%2FRust_learning"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNandem%2FRust_learning'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] f6ba2518afb7cacb51835855bbd260bf98a628b1
[INFO] checking Nandem/Rust_learning against master#45d050cde277b22a755847338f2acc2c7b834141 for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNandem%2FRust_learning" "/workspace/builds/worker-11/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Nandem/Rust_learning on toolchain 45d050cde277b22a755847338f2acc2c7b834141
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/Nandem/Rust_learning
[INFO] finished tweaking git repo https://github.com/Nandem/Rust_learning
[INFO] tweaked toml for git repo https://github.com/Nandem/Rust_learning written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/Nandem/Rust_learning already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "MAP_USER_ID=0" "-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" "+45d050cde277b22a755847338f2acc2c7b834141" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 7f781ebc755aec2f080037085f7bfc7635b6ea6b6e12159c2f799ab8de949ebf
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "7f781ebc755aec2f080037085f7bfc7635b6ea6b6e12159c2f799ab8de949ebf"`
[INFO] [stderr]     Checking learning v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:39:49
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn read_username_from_file1() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:55:49
[INFO] [stderr]    |
[INFO] [stderr] 55 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:62:49
[INFO] [stderr]    |
[INFO] [stderr] 62 | fn read_username_from_file3() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:49:13
[INFO] [stderr]     |
[INFO] [stderr] 49  |     match f.read_to_string(&mut s) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:58:7
[INFO] [stderr]     |
[INFO] [stderr] 58  |     f.read_to_string(&mut s)?;
[INFO] [stderr]     |       ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:39:49
[INFO] [stderr]    |
[INFO] [stderr] 39 | fn read_username_from_file1() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:55:49
[INFO] [stderr]    |
[INFO] [stderr] 55 | fn read_username_from_file2() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0433]: failed to resolve: use of undeclared type or module `io`
[INFO] [stderr]   --> src/errors/error1.rs:62:49
[INFO] [stderr]    |
[INFO] [stderr] 62 | fn read_username_from_file3() -> Result<String, io::Error> {
[INFO] [stderr]    |                                                 ^^ use of undeclared type or module `io`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:65:30
[INFO] [stderr]     |
[INFO] [stderr] 65  |     File::open("hello.txt")?.read_to_string(&mut s)?;
[INFO] [stderr]     |                              ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 6 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0433, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0433`.
[INFO] [stderr] error: could not compile `learning`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:49:13
[INFO] [stderr]     |
[INFO] [stderr] 49  |     match f.read_to_string(&mut s) {
[INFO] [stderr]     |             ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:58:7
[INFO] [stderr]     |
[INFO] [stderr] 58  |     f.read_to_string(&mut s)?;
[INFO] [stderr]     |       ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error[E0599]: no method named `read_to_string` found for struct `std::fs::File` in the current scope
[INFO] [stderr]    --> src/errors/error1.rs:65:30
[INFO] [stderr]     |
[INFO] [stderr] 65  |     File::open("hello.txt")?.read_to_string(&mut s)?;
[INFO] [stderr]     |                              ^^^^^^^^^^^^^^ method not found in `std::fs::File`
[INFO] [stderr]     |
[INFO] [stderr]     = help: items from traits can only be used if the trait is in scope
[INFO] [stderr]     = note: the following trait is implemented but not in scope; perhaps add a `use` for it:
[INFO] [stderr]             `use std::io::Read;`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 6 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0433, E0599.
[INFO] [stderr] For more information about an error, try `rustc --explain E0433`.
[INFO] [stderr] error: could not compile `learning`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "7f781ebc755aec2f080037085f7bfc7635b6ea6b6e12159c2f799ab8de949ebf"`
[INFO] running `"docker" "rm" "-f" "7f781ebc755aec2f080037085f7bfc7635b6ea6b6e12159c2f799ab8de949ebf"`
[INFO] [stdout] 7f781ebc755aec2f080037085f7bfc7635b6ea6b6e12159c2f799ab8de949ebf