[INFO] cloning repository https://github.com/BrookJeynes/flashcards-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/BrookJeynes/flashcards-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6f85eafdba9b3e8c87a8ba11c847187a15b81c09
[INFO] checking BrookJeynes/flashcards-rs against try#18c1d185ac7a6a3bf399296b35e4b2736809a756 for pr-146972
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBrookJeynes%2Fflashcards-rs" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/BrookJeynes/flashcards-rs
[INFO] finished tweaking git repo https://github.com/BrookJeynes/flashcards-rs
[INFO] tweaked toml for git repo https://github.com/BrookJeynes/flashcards-rs written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/BrookJeynes/flashcards-rs on toolchain 18c1d185ac7a6a3bf399296b35e4b2736809a756
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/BrookJeynes/flashcards-rs 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" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9f678c00ab0e654b2854b418027d6b9482354148d554ffb6688d6eee215fa262
[INFO] running `Command { std: "docker" "start" "-a" "9f678c00ab0e654b2854b418027d6b9482354148d554ffb6688d6eee215fa262", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9f678c00ab0e654b2854b418027d6b9482354148d554ffb6688d6eee215fa262", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9f678c00ab0e654b2854b418027d6b9482354148d554ffb6688d6eee215fa262", kill_on_drop: false }`
[INFO] [stdout] 9f678c00ab0e654b2854b418027d6b9482354148d554ffb6688d6eee215fa262
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:94a0c148923f5b2b52a63ef0eeb1882ad339ab61bce784c8077cbe41c61feb6c" "/opt/rustwide/cargo-home/bin/cargo" "+18c1d185ac7a6a3bf399296b35e4b2736809a756" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 72f8fcf33839456546ca52de468b962474bf1e301f62558dd9317bb517bd7c14
[INFO] running `Command { std: "docker" "start" "-a" "72f8fcf33839456546ca52de468b962474bf1e301f62558dd9317bb517bd7c14", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.49
[INFO] [stderr]    Compiling syn v1.0.107
[INFO] [stderr]    Compiling signal-hook v0.3.14
[INFO] [stderr]    Compiling parking_lot_core v0.9.6
[INFO] [stderr]    Compiling serde v1.0.152
[INFO] [stderr]    Compiling serde_json v1.0.91
[INFO] [stderr]     Checking unicode-segmentation v1.10.0
[INFO] [stderr]    Compiling xcb v0.8.2
[INFO] [stderr]     Checking bitvec v0.17.4
[INFO] [stderr]     Checking ryu v1.0.12
[INFO] [stderr]     Checking mio v0.8.5
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.49/src/lib.rs:92:30
[INFO] [stdout]    |
[INFO] [stdout] 92 |     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: failed to run custom build command for `xcb v0.8.2`
[INFO] [stderr] note: To improve backtraces for build dependencies, set the CARGO_PROFILE_DEV_BUILD_OVERRIDE_DEBUG=true environment variable to enable debug information generation.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/target/debug/build/xcb-c91eede5a72fa2b1/build-script-build` (exit status: 101)
[INFO] [stderr]   --- stderr
[INFO] [stderr]   error occured in handler:  ('request: ', ('xcb', 'Xevie', 'SelectInput'))
[INFO] [stderr]   Traceback (most recent call last):
[INFO] [stderr]     File "/opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/rs_client.py", line 2448, in <module>
[INFO] [stderr]       module.generate()
[INFO] [stderr]     File "/opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/xcbgen/state.py", line 108, in generate
[INFO] [stderr]       self.close()
[INFO] [stderr]     File "/opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/rs_client.py", line 296, in rs_close
[INFO] [stderr]       _f.writeout(os.path.join(module.rs_srcdir, "ffi", "%s.rs" % _module_name(_ns.ext_name)))
[INFO] [stderr]     File "/opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/rs_client.py", line 114, in writeout
[INFO] [stderr]       with open(path, 'w') as f:
[INFO] [stderr]            ^^^^^^^^^^^^^^^
[INFO] [stderr]   OSError: [Errno 30] Read-only file system: '/opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/src/ffi/xevie.rs'
[INFO] [stderr] 
[INFO] [stderr]   thread 'main' (248) panicked at /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/build.rs:75:17:
[INFO] [stderr]   processing of /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xcb-0.8.2/xml/xevie.xml returned non-zero (1)
[INFO] [stderr]   stack backtrace:
[INFO] [stderr]      0:     0x56db8f016762 - std[f5b73ab62149f354]::backtrace_rs::backtrace::libunwind::trace
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/../../backtrace/src/backtrace/libunwind.rs:117:9
[INFO] [stderr]      1:     0x56db8f016762 - std[f5b73ab62149f354]::backtrace_rs::backtrace::trace_unsynchronized::<std[f5b73ab62149f354]::sys::backtrace::_print_fmt::{closure#1}>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/../../backtrace/src/backtrace/mod.rs:66:14
[INFO] [stderr]      2:     0x56db8f016762 - std[f5b73ab62149f354]::sys::backtrace::_print_fmt
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/sys/backtrace.rs:68:9
[INFO] [stderr]      3:     0x56db8f016762 - <<std[f5b73ab62149f354]::sys::backtrace::BacktraceLock>::print::DisplayBacktrace as core[7c9bcc88e4c2614d]::fmt::Display>::fmt
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/sys/backtrace.rs:38:26
[INFO] [stderr]      4:     0x56db8f028317 - <core[7c9bcc88e4c2614d]::fmt::rt::Argument>::fmt
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/core/src/fmt/rt.rs:152:76
[INFO] [stderr]      5:     0x56db8f028317 - core[7c9bcc88e4c2614d]::fmt::write
[INFO] [stderr]      6:     0x56db8f01b216 - std[f5b73ab62149f354]::io::default_write_fmt::<std[f5b73ab62149f354]::sys::stdio::unix::Stderr>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/io/mod.rs:639:11
[INFO] [stderr]      7:     0x56db8f01b216 - <std[f5b73ab62149f354]::sys::stdio::unix::Stderr as std[f5b73ab62149f354]::io::Write>::write_fmt
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/io/mod.rs:1994:13
[INFO] [stderr]      8:     0x56db8effacea - <std[f5b73ab62149f354]::sys::backtrace::BacktraceLock>::print
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/sys/backtrace.rs:41:9
[INFO] [stderr]      9:     0x56db8effacea - std[f5b73ab62149f354]::panicking::default_hook::{closure#0}
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:292:27
[INFO] [stderr]     10:     0x56db8f012541 - std[f5b73ab62149f354]::panicking::default_hook
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:319:9
[INFO] [stderr]     11:     0x56db8f0126fb - std[f5b73ab62149f354]::panicking::panic_with_hook
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:825:13
[INFO] [stderr]     12:     0x56db8effada8 - std[f5b73ab62149f354]::panicking::panic_handler::{closure#0}
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:698:13
[INFO] [stderr]     13:     0x56db8eff2909 - std[f5b73ab62149f354]::sys::backtrace::__rust_end_short_backtrace::<std[f5b73ab62149f354]::panicking::panic_handler::{closure#0}, !>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/sys/backtrace.rs:176:18
[INFO] [stderr]     14:     0x56db8effb70d - __rustc[86b423d158974b9]::rust_begin_unwind
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:689:5
[INFO] [stderr]     15:     0x56db8f02895c - core[7c9bcc88e4c2614d]::panicking::panic_fmt
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/core/src/panicking.rs:80:14
[INFO] [stderr]     16:     0x56db8efdf56b - build_script_build[584e47eea45a0abb]::main::{closure#0}
[INFO] [stderr]     17:     0x56db8efdd29d - build_script_build[584e47eea45a0abb]::visit_xml::<build_script_build[584e47eea45a0abb]::main::{closure#0}>
[INFO] [stderr]     18:     0x56db8efdfd3a - build_script_build[584e47eea45a0abb]::main
[INFO] [stderr]     19:     0x56db8efe2953 - <fn() as core[7c9bcc88e4c2614d]::ops::function::FnOnce<()>>::call_once
[INFO] [stderr]     20:     0x56db8efdeb76 - std[f5b73ab62149f354]::sys::backtrace::__rust_begin_short_backtrace::<fn(), ()>
[INFO] [stderr]     21:     0x56db8efdf059 - std[f5b73ab62149f354]::rt::lang_start::<()>::{closure#0}
[INFO] [stderr]     22:     0x56db8f0116ba - <&dyn core[7c9bcc88e4c2614d]::ops::function::Fn<(), Output = i32> + core[7c9bcc88e4c2614d]::marker::Sync + core[7c9bcc88e4c2614d]::panic::unwind_safe::RefUnwindSafe as core[7c9bcc88e4c2614d]::ops::function::FnOnce<()>>::call_once
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/core/src/ops/function.rs:287:21
[INFO] [stderr]     23:     0x56db8f0116ba - std[f5b73ab62149f354]::panicking::catch_unwind::do_call::<&dyn core[7c9bcc88e4c2614d]::ops::function::Fn<(), Output = i32> + core[7c9bcc88e4c2614d]::marker::Sync + core[7c9bcc88e4c2614d]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:581:40
[INFO] [stderr]     24:     0x56db8f0116ba - std[f5b73ab62149f354]::panicking::catch_unwind::<i32, &dyn core[7c9bcc88e4c2614d]::ops::function::Fn<(), Output = i32> + core[7c9bcc88e4c2614d]::marker::Sync + core[7c9bcc88e4c2614d]::panic::unwind_safe::RefUnwindSafe>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:544:19
[INFO] [stderr]     25:     0x56db8f0116ba - std[f5b73ab62149f354]::panic::catch_unwind::<&dyn core[7c9bcc88e4c2614d]::ops::function::Fn<(), Output = i32> + core[7c9bcc88e4c2614d]::marker::Sync + core[7c9bcc88e4c2614d]::panic::unwind_safe::RefUnwindSafe, i32>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panic.rs:359:14
[INFO] [stderr]     26:     0x56db8f0116ba - std[f5b73ab62149f354]::rt::lang_start_internal::{closure#0}
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/rt.rs:175:24
[INFO] [stderr]     27:     0x56db8f0116ba - std[f5b73ab62149f354]::panicking::catch_unwind::do_call::<std[f5b73ab62149f354]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:581:40
[INFO] [stderr]     28:     0x56db8f0116ba - std[f5b73ab62149f354]::panicking::catch_unwind::<isize, std[f5b73ab62149f354]::rt::lang_start_internal::{closure#0}>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panicking.rs:544:19
[INFO] [stderr]     29:     0x56db8f0116ba - std[f5b73ab62149f354]::panic::catch_unwind::<std[f5b73ab62149f354]::rt::lang_start_internal::{closure#0}, isize>
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/panic.rs:359:14
[INFO] [stderr]     30:     0x56db8f0116ba - std[f5b73ab62149f354]::rt::lang_start_internal
[INFO] [stderr]                                  at /rustc/18c1d185ac7a6a3bf399296b35e4b2736809a756/library/std/src/rt.rs:171:5
[INFO] [stderr]     31:     0x56db8efdeaf1 - std[f5b73ab62149f354]::rt::lang_start::<()>
[INFO] [stderr]     32:     0x56db8efe2ce5 - main
[INFO] [stderr]     33:     0x7e4b51b7c1ca - <unknown>
[INFO] [stderr]     34:     0x7e4b51b7c28b - __libc_start_main
[INFO] [stderr]     35:     0x56db8efdccd5 - _start
[INFO] [stderr]     36:                0x0 - <unknown>
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "72f8fcf33839456546ca52de468b962474bf1e301f62558dd9317bb517bd7c14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "72f8fcf33839456546ca52de468b962474bf1e301f62558dd9317bb517bd7c14", kill_on_drop: false }`
[INFO] [stdout] 72f8fcf33839456546ca52de468b962474bf1e301f62558dd9317bb517bd7c14
