[INFO] cloning repository https://github.com/DataScienceDIY/quick_search
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/DataScienceDIY/quick_search" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDataScienceDIY%2Fquick_search", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDataScienceDIY%2Fquick_search'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f9171b56e974012ba279c3ac42741b3fc8af7a83
[INFO] checking DataScienceDIY/quick_search against 34f4a807e2d84184fff4e42d4539092569b6fcd6 for pr-164081
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FDataScienceDIY%2Fquick_search" "/workspace/builds/worker-1-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc1/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-1-tc1/source/rust-toolchain.toml
[INFO] started tweaking git repo https://github.com/DataScienceDIY/quick_search
[INFO] finished tweaking git repo https://github.com/DataScienceDIY/quick_search
[INFO] tweaked toml for git repo https://github.com/DataScienceDIY/quick_search written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/DataScienceDIY/quick_search on toolchain 34f4a807e2d84184fff4e42d4539092569b6fcd6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+34f4a807e2d84184fff4e42d4539092569b6fcd6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/DataScienceDIY/quick_search 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" "+34f4a807e2d84184fff4e42d4539092569b6fcd6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded gethostname v1.0.2
[INFO] [stderr]   Downloaded ashpd v0.11.1
[INFO] [stderr]   Downloaded wayland-scanner v0.31.11
[INFO] [stderr]   Downloaded wayland-client v0.31.15
[INFO] [stderr]   Downloaded zvariant_utils v3.5.0
[INFO] [stderr]   Downloaded zvariant_derive v5.13.1
[INFO] [stderr]   Downloaded zerovec-derive v0.11.5
[INFO] [stderr]   Downloaded wayland-backend v0.3.16
[INFO] [stderr]   Downloaded displaydoc v0.2.4
[INFO] [stderr]   Downloaded zvariant v5.13.1
[INFO] [stderr]   Downloaded enumflags2_derive v0.7.10
[INFO] [stderr]   Downloaded enumflags2 v0.7.10
[INFO] [stderr]   Downloaded xdg-home v1.2.0
[INFO] [stderr]   Downloaded zbus v5.4.0
[INFO] [stderr]   Downloaded zbus_macros v5.4.0
[INFO] [stderr]   Downloaded piper v0.2.3
[INFO] [stderr]   Downloaded event-listener-strategy v0.5.2
[INFO] [stderr]   Downloaded futures-lite v2.3.0
[INFO] [stderr]   Downloaded async-broadcast v0.7.1
[INFO] [stderr]   Downloaded async-process v2.2.3
[INFO] [stderr]   Downloaded async-io v2.3.3
[INFO] [stderr]   Downloaded polling v3.7.1
[INFO] [stderr]   Downloaded async-executor v1.12.0
[INFO] [stderr]   Downloaded async-signal v0.2.8
[INFO] [stderr]   Downloaded zlib-rs v0.6.7
[INFO] [stderr]   Downloaded toml v1.1.3+spec-1.1.0
[INFO] [stderr]   Downloaded type1-encoding-parser v0.1.1
[INFO] [stderr]   Downloaded postscript v0.14.1
[INFO] [stderr]   Downloaded pom v1.1.0
[INFO] [stderr]   Downloaded lopdf v0.42.0
[INFO] [stderr]   Downloaded ecb v0.1.2
[INFO] [stderr]   Downloaded cff-parser v0.2.0
[INFO] [stderr]   Downloaded mimalloc v0.1.52
[INFO] [stderr]   Downloaded metaflac v0.2.8
[INFO] [stderr]   Downloaded rust_xlsxwriter v0.98.2
[INFO] [stderr]   Downloaded filetime v0.2.27
[INFO] [stderr]   Downloaded ogg_pager v0.6.1
[INFO] [stderr]   Downloaded infer v0.15.0
[INFO] [stderr]   Downloaded cfb v0.7.3
[INFO] [stderr]   Downloaded globset v0.4.19
[INFO] [stderr]   Downloaded divan-macros v0.1.21
[INFO] [stderr]   Downloaded condtype v1.3.0
[INFO] [stderr]   Downloaded lofty_attr v0.10.0
[INFO] [stderr]   Downloaded uuid v1.8.0
[INFO] [stderr]   Downloaded windows-core v0.62.1
[INFO] [stderr]   Downloaded ctrlc v3.5.0
[INFO] [stderr]   Downloaded lofty v0.19.2
[INFO] [stderr]   Downloaded divan v0.1.21
[INFO] [stderr]   Downloaded chardetng v1.0.0
[INFO] [stderr]   Downloaded windows-targets v0.53.4
[INFO] [stderr]   Downloaded id3 v1.17.1
[INFO] [stderr]   Downloaded libmimalloc-sys v0.1.49
[INFO] [stderr]   Downloaded keyring v3.6.3
[INFO] [stderr]   Downloaded bstr v1.13.0
[INFO] [stderr]   Downloaded egui_extras v0.32.3
[INFO] [stderr]   Downloaded dbus v0.9.12
[INFO] [stderr]   Downloaded docx-rs v0.4.21
[INFO] [stderr]   Downloaded open v5.4.0
[INFO] [stderr]   Downloaded dbus-secret-service v4.1.0
[INFO] [stderr]   Downloaded global-hotkey v0.8.0
[INFO] [stderr]   Downloaded pdf-writer v0.15.0
[INFO] [stderr]   Downloaded emath v0.32.3
[INFO] [stderr]   Downloaded libdbus-sys v0.2.7
[INFO] [stderr]   Downloaded ron v0.10.1
[INFO] [stderr]   Downloaded xcursor v0.3.11
[INFO] [stderr]   Downloaded bytemuck_derive v1.11.0
[INFO] [stderr]   Downloaded epaint v0.32.3
[INFO] [stderr]   Downloaded ecolor v0.32.3
[INFO] [stderr]   Downloaded openssl v0.10.76
[INFO] [stderr]   Downloaded egui v0.32.3
[INFO] [stderr]   Downloaded eframe v0.32.3
[INFO] [stderr]   Downloaded openssl-src v300.6.1+3.6.3
[INFO] [stderr]   Downloaded egui_glow v0.32.3
[INFO] [stderr]   Downloaded webbrowser v1.2.2
[INFO] [stderr]   Downloaded egui-winit v0.32.3
[INFO] [stderr]   Downloaded egui-wgpu v0.32.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:77db811e55d90add9212f6832c23229e3de5f1c1f9905e8cb07319ea15df73ac" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c
[INFO] running `Command { std: "docker" "start" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c" "/opt/rustwide/cargo-home/bin/cargo" "+34f4a807e2d84184fff4e42d4539092569b6fcd6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-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" "-w" "/opt/rustwide/workdir" "--user" "0:0" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c" "/opt/rustwide/cargo-home/bin/cargo" "+34f4a807e2d84184fff4e42d4539092569b6fcd6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.107
[INFO] [stderr]    Compiling unicode-ident v1.0.12
[INFO] [stderr]    Compiling libc v0.2.189
[INFO] [stderr]    Compiling pkg-config v0.3.30
[INFO] [stderr]    Compiling autocfg v1.3.0
[INFO] [stderr]     Checking smallvec v1.13.2
[INFO] [stderr]    Compiling rustix v1.1.4
[INFO] [stderr]    Compiling quote v1.0.47
[INFO] [stderr]    Compiling serde v1.0.229
[INFO] [stderr]     Checking memchr v2.7.4
[INFO] [stderr]    Compiling typenum v1.17.0
[INFO] [stderr]    Compiling generic-array v0.14.7
[INFO] [stderr]    Compiling crossbeam-utils v0.8.20
[INFO] [stderr]     Checking bitflags v2.13.1
[INFO] [stderr]     Checking crc32fast v1.5.0
[INFO] [stderr]     Checking miniz_oxide v0.8.9
[INFO] [stderr]     Checking zlib-rs v0.6.7
[INFO] [stderr]     Checking ttf-parser v0.25.1
[INFO] [stderr]    Compiling thiserror v2.0.19
[INFO] [stderr]     Checking winnow v1.0.4
[INFO] [stderr]     Checking equivalent v1.0.1
[INFO] [stderr]     Checking encoding_rs v0.8.35
[INFO] [stderr]     Checking indexmap v2.14.0
[INFO] [stderr]    Compiling num-traits v0.2.19
[INFO] [stderr]     Checking itoa v1.0.11
[INFO] [stderr]     Checking tinyvec_macros v0.1.1
[INFO] [stderr]     Checking rand_core v0.10.1
[INFO] [stderr]    Compiling getrandom v0.4.3
[INFO] [stderr]     Checking cpufeatures v0.2.12
[INFO] [stderr]     Checking tinyvec v1.11.0
[INFO] [stderr]     Checking cpufeatures v0.3.0
[INFO] [stderr]     Checking aho-corasick v1.1.3
[INFO] [stderr]     Checking chacha20 v0.10.1
[INFO] [stderr]    Compiling nix v0.30.1
[INFO] [stderr]     Checking unicode-properties v0.1.4
[INFO] [stderr]     Checking unicode-bidi v0.3.18
[INFO] [stderr]    Compiling zstd-safe v7.2.4
[INFO] [stderr]     Checking regex-syntax v0.8.4
[INFO] [stderr]    Compiling syn v2.0.66
[INFO] [stderr]    Compiling syn v3.0.3
[INFO] [stderr]     Checking hashbrown v0.16.1
[INFO] [stderr]    Compiling jobserver v0.1.32
[INFO] [stderr]     Checking unicode-normalization v0.1.25
[INFO] [stderr]     Checking crossbeam-channel v0.5.16
[INFO] [stderr]     Checking nom v8.0.0
[INFO] [stderr]     Checking rangemap v1.7.1
[INFO] [stderr]    Compiling cc v1.4.0
[INFO] [stderr]     Checking stringprep v0.1.5
[INFO] [stderr]     Checking weezl v0.1.12
[INFO] [stderr]     Checking pom v1.1.0
[INFO] [stderr]     Checking uuid v1.8.0
[INFO] [stderr]     Checking flate2 v1.1.9
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking base64ct v1.8.0
[INFO] [stderr]     Checking hashlink v0.11.1
[INFO] [stderr]     Checking cfb v0.7.3
[INFO] [stderr]     Checking quick-xml v0.41.0
[INFO] [stderr]     Checking euclid v0.20.14
[INFO] [stderr]     Checking toml_parser v1.1.3+spec-1.1.0
[INFO] [stderr]     Checking type1-encoding-parser v0.1.1
[INFO] [stderr]     Checking password-hash v0.5.0
[INFO] [stderr]     Checking crypto-common v0.1.6
[INFO] [stderr]     Checking block-padding v0.3.3
[INFO] [stderr]     Checking block-buffer v0.10.4
[INFO] [stderr]     Checking digest v0.10.7
[INFO] [stderr]     Checking inout v0.1.4
[INFO] [stderr]     Checking bstr v1.13.0
[INFO] [stderr]     Checking ogg_pager v0.6.1
[INFO] [stderr]     Checking serde_spanned v1.1.1
[INFO] [stderr]     Checking toml_datetime v1.1.1+spec-1.1.0
[INFO] [stderr]     Checking cipher v0.4.4
[INFO] [stderr]     Checking toml_writer v1.1.2+spec-1.1.0
[INFO] [stderr]     Checking cff-parser v0.2.0
[INFO] [stderr]     Checking postscript v0.14.1
[INFO] [stderr]     Checking chrono v0.4.44
[INFO] [stderr]     Checking sha2 v0.10.8
[INFO] [stderr]     Checking getrandom v0.2.15
[INFO] [stderr]     Checking inotify-sys v0.1.5
[INFO] [stderr]     Checking cbc v0.1.2
[INFO] [stderr]     Checking aes v0.8.4
[INFO] [stderr]     Checking ecb v0.1.2
[INFO] [stderr]     Checking md-5 v0.10.6
[INFO] [stderr]     Checking inotify v0.9.6
[INFO] [stderr]     Checking filetime v0.2.27
[INFO] [stderr]     Checking rand v0.10.2
[INFO] [stderr]     Checking mio v0.8.11
[INFO] [stderr]     Checking blake2 v0.10.6
[INFO] [stderr]     Checking toml v1.1.3+spec-1.1.0
[INFO] [stderr]     Checking infer v0.15.0
[INFO] [stderr]     Checking zip v0.6.6
[INFO] [stderr]     Checking regex-automata v0.4.7
[INFO] [stderr]     Checking chardetng v1.0.0
[INFO] [stderr]     Checking pin-project-lite v0.2.14
[INFO] [stderr]    Compiling openssl-src v300.6.1+3.6.3
[INFO] [stderr]     Checking notify v6.1.1 (/opt/rustwide/workdir/vendor/notify)
[INFO] [stderr]     Checking bumpalo v3.20.3
[INFO] [stderr]     Checking typed-path v0.12.3
[INFO] [stderr]    Compiling serde_json v1.0.151
[INFO] [stderr]     Checking libloading v0.8.9
[INFO] [stdout] warning: use of deprecated associated function `core::num::<impl usize>::max_value`: replaced by the `MAX` associated constant on this type
[INFO] [stdout]    --> vendor/notify/src/poll.rs:310:24
[INFO] [stdout]     |
[INFO] [stdout] 310 |                 usize::max_value()
[INFO] [stdout]     |                        ^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking condtype v1.3.0
[INFO] [stderr]     Checking zopfli v0.8.3
[INFO] [stderr]     Checking regex-lite v0.1.9
[INFO] [stderr]     Checking pdf-writer v0.15.0
[INFO] [stderr]     Checking id3 v1.17.1
[INFO] [stderr]     Checking metaflac v0.2.8
[INFO] [stderr]     Checking ctrlc v3.5.0
[INFO] [stderr]     Checking dlib v0.5.3
[INFO] [stderr]    Compiling wayland-sys v0.31.11
[INFO] [stderr]    Compiling slab v0.4.9
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling rustix v0.38.34
[INFO] [stderr]     Checking tracing-core v0.1.32
[INFO] [stderr]     Checking linux-raw-sys v0.4.14
[INFO] [stderr]    Compiling openssl-sys v0.9.117
[INFO] [stderr]    Compiling zstd-sys v2.0.16+zstd.1.5.7
[INFO] [stderr]    Compiling libmimalloc-sys v0.1.49
[INFO] [stderr]    Compiling libsqlite3-sys v0.37.0
[INFO] [stderr]    Compiling wayland-backend v0.3.16
[INFO] [stderr]    Compiling wayland-client v0.31.15
[INFO] [stderr]     Checking parking v2.2.0
[INFO] [stderr]    Compiling serde_core v1.0.229
[INFO] [stderr]     Checking event-listener v5.4.2
[INFO] [stderr]     Checking zip v8.6.0
[INFO] [stderr]     Checking percent-encoding v2.3.1
[INFO] [stderr]     Checking event-listener-strategy v0.5.2
[INFO] [stderr]     Checking fastrand v2.1.0
[INFO] [stderr]     Checking concurrent-queue v2.5.0
[INFO] [stderr] error: could not compile `syn` (lib)
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/34f4a807e2d84184fff4e42d4539092569b6fcd6/bin/rustc --crate-name syn --edition=2021 /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/syn-3.0.3/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat,unused-externs-silent --crate-type lib --emit=dep-info,metadata,link -Z embed-metadata=no -C embed-bitcode=no --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="extra-traits"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("clone-impls", "default", "derive", "extra-traits", "fold", "full", "parsing", "printing", "proc-macro", "test", "visit", "visit-mut"))' -C metadata=c9e544191175d77c -C extra-filename=-bf08411e5b43c5e9 --out-dir /opt/rustwide/target/debug/build/syn/bf08411e5b43c5e9/out -L dependency=/opt/rustwide/target/debug/build/proc-macro2/e3152cf0eab70855/out -L dependency=/opt/rustwide/target/debug/build/unicode-ident/f2de522ba645d884/out --extern proc_macro2=/opt/rustwide/target/debug/build/proc-macro2/e3152cf0eab70855/out/libproc_macro2-e3152cf0eab70855.rmeta --extern quote=/opt/rustwide/target/debug/build/quote/1cc08a6458cb274b/out/libquote-1cc08a6458cb274b.rmeta --extern unicode_ident=/opt/rustwide/target/debug/build/unicode-ident/f2de522ba645d884/out/libunicode_ident-f2de522ba645d884.rmeta --cap-lints allow --cap-lints=forbid --force-warn=unused_crate_dependencies` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `rustix` (lib)
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/34f4a807e2d84184fff4e42d4539092569b6fcd6/bin/rustc --crate-name rustix --edition=2021 /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/rustix-1.1.4/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat,unused-externs-silent --crate-type lib --emit=dep-info,metadata -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="alloc"' --cfg 'feature="default"' --cfg 'feature="event"' --cfg 'feature="fs"' --cfg 'feature="net"' --cfg 'feature="pipe"' --cfg 'feature="process"' --cfg 'feature="shm"' --cfg 'feature="std"' --cfg 'feature="system"' --cfg 'feature="termios"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("all-apis", "alloc", "core", "default", "event", "fs", "io_uring", "libc", "libc_errno", "linux_4_11", "linux_5_1", "linux_5_11", "linux_latest", "mm", "mount", "net", "param", "pipe", "process", "pty", "rand", "runtime", "rustc-dep-of-std", "rustc-std-workspace-alloc", "shm", "std", "stdio", "system", "termios", "thread", "time", "try_close", "use-explicitly-provided-auxv", "use-libc", "use-libc-auxv"))' -C metadata=6d841e2f4ed8c85a -C extra-filename=-4c93d6502d484832 --out-dir /opt/rustwide/target/debug/build/rustix/4c93d6502d484832/out -L dependency=/opt/rustwide/target/debug/build/serde_core/182ae46cbfb5dc43/out --extern bitflags=/opt/rustwide/target/debug/build/bitflags/a362a186fea91942/out/libbitflags-a362a186fea91942.rmeta --extern linux_raw_sys=/opt/rustwide/target/debug/build/linux-raw-sys/ff271329eb221e3a/out/liblinux_raw_sys-ff271329eb221e3a.rmeta --cap-lints allow --cap-lints=forbid --force-warn=unused_crate_dependencies --cfg static_assertions --cfg lower_upper_exp_for_non_zero --cfg rustc_diagnostics --cfg linux_raw_dep --cfg linux_raw --cfg linux_like --cfg linux_kernel` (signal: 9, SIGKILL: kill)
[INFO] running `Command { std: "docker" "inspect" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c", kill_on_drop: false }`
[INFO] [stdout] b2e1160cfb44a877fce6a95a1982511c3d2416473db0837b50ad7e663818522c