[INFO] cloning repository https://github.com/underscorenico/sqlite_clone [INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/underscorenico/sqlite_clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Funderscorenico%2Fsqlite_clone", kill_on_drop: false }` [INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Funderscorenico%2Fsqlite_clone'... [INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }` [INFO] [stdout] effb10648ed02399ad8c43431e633f530001f0de [INFO] checking underscorenico/sqlite_clone against try#c659ee110de67e82444e4b6c8407c1a9af9c2cf6 for pr-145608 [INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Funderscorenico%2Fsqlite_clone" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }` [INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'... [INFO] [stderr] done. [INFO] started tweaking git repo https://github.com/underscorenico/sqlite_clone [INFO] finished tweaking git repo https://github.com/underscorenico/sqlite_clone [INFO] tweaked toml for git repo https://github.com/underscorenico/sqlite_clone written to /workspace/builds/worker-5-tc2/source/Cargo.toml [INFO] validating manifest of git repo https://github.com/underscorenico/sqlite_clone on toolchain c659ee110de67e82444e4b6c8407c1a9af9c2cf6 [INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }` [INFO] crate git repo https://github.com/underscorenico/sqlite_clone 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" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }` [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] [stderr] Blocking waiting for file lock on package cache [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }` [INFO] [stdout] 4f84b279ea667dfda64a9abf317d4c55ba4edf872a83352ba5e539c507d5b285 [INFO] running `Command { std: "docker" "start" "-a" "4f84b279ea667dfda64a9abf317d4c55ba4edf872a83352ba5e539c507d5b285", kill_on_drop: false }` [INFO] running `Command { std: "docker" "inspect" "4f84b279ea667dfda64a9abf317d4c55ba4edf872a83352ba5e539c507d5b285", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "4f84b279ea667dfda64a9abf317d4c55ba4edf872a83352ba5e539c507d5b285", kill_on_drop: false }` [INFO] [stdout] 4f84b279ea667dfda64a9abf317d4c55ba4edf872a83352ba5e539c507d5b285 [INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }` [INFO] [stdout] 95c8887bd77554d3d720331b2aa78598537309d5f4439759824cd5bc7fd17e4c [INFO] running `Command { std: "docker" "start" "-a" "95c8887bd77554d3d720331b2aa78598537309d5f4439759824cd5bc7fd17e4c", kill_on_drop: false }` [INFO] [stderr] Checking sqlite v0.1.0 (/opt/rustwide/workdir) [INFO] [stdout] warning: unused import: `Read` [INFO] [stdout] --> src/main.rs:1:36 [INFO] [stdout] | [INFO] [stdout] 1 | use std::io::{self, stdin, stdout, Read, Write}; [INFO] [stdout] | ^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `META_COMMAND_SUCCESS` should have an upper camel case name [INFO] [stdout] --> src/main.rs:30:5 [INFO] [stdout] | [INFO] [stdout] 30 | META_COMMAND_SUCCESS, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `MetaCommandSuccess` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(non_camel_case_types)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `META_COMMAND_UNRECOGNIZED_COMMAND` should have an upper camel case name [INFO] [stdout] --> src/main.rs:31:5 [INFO] [stdout] | [INFO] [stdout] 31 | META_COMMAND_UNRECOGNIZED_COMMAND, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `MetaCommandUnrecognizedCommand` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `PREPARE_SUCCESS` should have an upper camel case name [INFO] [stdout] --> src/main.rs:35:5 [INFO] [stdout] | [INFO] [stdout] 35 | PREPARE_SUCCESS, [INFO] [stdout] | ^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `PrepareSuccess` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `PREPARE_UNRECOGNIZED_STATEMENT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:36:5 [INFO] [stdout] | [INFO] [stdout] 36 | PREPARE_UNRECOGNIZED_STATEMENT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `PrepareUnrecognizedStatement` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `STATEMENT_INSERT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:40:5 [INFO] [stdout] | [INFO] [stdout] 40 | STATEMENT_INSERT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `StatementInsert` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `STATEMENT_SELECT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:41:5 [INFO] [stdout] | [INFO] [stdout] 41 | STATEMENT_SELECT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `StatementSelect` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused import: `Read` [INFO] [stdout] --> src/main.rs:1:36 [INFO] [stdout] | [INFO] [stdout] 1 | use std::io::{self, stdin, stdout, Read, Write}; [INFO] [stdout] | ^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_imports)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unnecessary parentheses around `match` scrutinee expression [INFO] [stdout] --> src/main.rs:64:11 [INFO] [stdout] | [INFO] [stdout] 64 | match (statement) { [INFO] [stdout] | ^ ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_parens)]` on by default [INFO] [stdout] help: remove these parentheses [INFO] [stdout] | [INFO] [stdout] 64 - match (statement) { [INFO] [stdout] 64 + match statement { [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `META_COMMAND_SUCCESS` should have an upper camel case name [INFO] [stdout] --> src/main.rs:30:5 [INFO] [stdout] | [INFO] [stdout] 30 | META_COMMAND_SUCCESS, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `MetaCommandSuccess` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(non_camel_case_types)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `META_COMMAND_UNRECOGNIZED_COMMAND` should have an upper camel case name [INFO] [stdout] --> src/main.rs:31:5 [INFO] [stdout] | [INFO] [stdout] 31 | META_COMMAND_UNRECOGNIZED_COMMAND, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `MetaCommandUnrecognizedCommand` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `PREPARE_SUCCESS` should have an upper camel case name [INFO] [stdout] --> src/main.rs:35:5 [INFO] [stdout] | [INFO] [stdout] 35 | PREPARE_SUCCESS, [INFO] [stdout] | ^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `PrepareSuccess` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `PREPARE_UNRECOGNIZED_STATEMENT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:36:5 [INFO] [stdout] | [INFO] [stdout] 36 | PREPARE_UNRECOGNIZED_STATEMENT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `PrepareUnrecognizedStatement` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `STATEMENT_INSERT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:40:5 [INFO] [stdout] | [INFO] [stdout] 40 | STATEMENT_INSERT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `StatementInsert` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variant `STATEMENT_SELECT` should have an upper camel case name [INFO] [stdout] --> src/main.rs:41:5 [INFO] [stdout] | [INFO] [stdout] 41 | STATEMENT_SELECT, [INFO] [stdout] | ^^^^^^^^^^^^^^^^ help: convert the identifier to upper camel case: `StatementSelect` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unnecessary parentheses around `match` scrutinee expression [INFO] [stdout] --> src/main.rs:64:11 [INFO] [stdout] | [INFO] [stdout] 64 | match (statement) { [INFO] [stdout] | ^ ^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_parens)]` on by default [INFO] [stdout] help: remove these parentheses [INFO] [stdout] | [INFO] [stdout] 64 - match (statement) { [INFO] [stdout] 64 + match statement { [INFO] [stdout] | [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0170]: pattern binding `META_COMMAND_SUCCESS` is named the same as one of the variants of the type `MetaCommandResult` [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: to match on the variant, qualify the path: `MetaCommandResult::META_COMMAND_SUCCESS` [INFO] [stdout] | [INFO] [stdout] = note: `#[deny(bindings_with_variant_name)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0170]: pattern binding `META_COMMAND_UNRECOGNIZED_COMMAND` is named the same as one of the variants of the type `MetaCommandResult` [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: to match on the variant, qualify the path: `MetaCommandResult::META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0170]: pattern binding `META_COMMAND_SUCCESS` is named the same as one of the variants of the type `MetaCommandResult` [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: to match on the variant, qualify the path: `MetaCommandResult::META_COMMAND_SUCCESS` [INFO] [stdout] | [INFO] [stdout] = note: `#[deny(bindings_with_variant_name)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] error[E0170]: pattern binding `META_COMMAND_UNRECOGNIZED_COMMAND` is named the same as one of the variants of the type `MetaCommandResult` [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: to match on the variant, qualify the path: `MetaCommandResult::META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unreachable pattern [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | -------------------- matches any value [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no value can reach this [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unreachable_patterns)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unreachable pattern [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | -------------------- matches any value [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no value can reach this [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unreachable_patterns)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `META_COMMAND_SUCCESS` [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_META_COMMAND_SUCCESS` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `META_COMMAND_SUCCESS` [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_META_COMMAND_SUCCESS` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(unused_variables)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: unused variable: `META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_META_COMMAND_UNRECOGNIZED_COMMAND` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: enum `PrepareStatementResult` is never used [INFO] [stdout] --> src/main.rs:34:6 [INFO] [stdout] | [INFO] [stdout] 34 | enum PrepareStatementResult { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: enum `PrepareStatementResult` is never used [INFO] [stdout] --> src/main.rs:34:6 [INFO] [stdout] | [INFO] [stdout] 34 | enum PrepareStatementResult { [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^ [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(dead_code)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `META_COMMAND_SUCCESS` should have a snake case name [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `meta_command_success` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(non_snake_case)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `META_COMMAND_SUCCESS` should have a snake case name [INFO] [stdout] --> src/main.rs:17:17 [INFO] [stdout] | [INFO] [stdout] 17 | META_COMMAND_SUCCESS => break, [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `meta_command_success` [INFO] [stdout] | [INFO] [stdout] = note: `#[warn(non_snake_case)]` on by default [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `META_COMMAND_UNRECOGNIZED_COMMAND` should have a snake case name [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `meta_command_unrecognized_command` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] warning: variable `META_COMMAND_UNRECOGNIZED_COMMAND` should have a snake case name [INFO] [stdout] --> src/main.rs:18:17 [INFO] [stdout] | [INFO] [stdout] 18 | META_COMMAND_UNRECOGNIZED_COMMAND => println!("Unrecognized command '{}'", command), [INFO] [stdout] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `meta_command_unrecognized_command` [INFO] [stdout] [INFO] [stdout] [INFO] [stdout] For more information about this error, try `rustc --explain E0170`. [INFO] [stdout] [INFO] [stdout] For more information about this error, try `rustc --explain E0170`. [INFO] [stdout] [INFO] [stderr] error: could not compile `sqlite` (bin "sqlite" test) due to 2 previous errors; 14 warnings emitted [INFO] [stderr] warning: build failed, waiting for other jobs to finish... [INFO] [stderr] error: could not compile `sqlite` (bin "sqlite") due to 2 previous errors; 14 warnings emitted [INFO] running `Command { std: "docker" "inspect" "95c8887bd77554d3d720331b2aa78598537309d5f4439759824cd5bc7fd17e4c", kill_on_drop: false }` [INFO] running `Command { std: "docker" "rm" "-f" "95c8887bd77554d3d720331b2aa78598537309d5f4439759824cd5bc7fd17e4c", kill_on_drop: false }` [INFO] [stdout] 95c8887bd77554d3d720331b2aa78598537309d5f4439759824cd5bc7fd17e4c