tokio-net 0.2.0-alpha.4

Event loop that drives Tokio I/O resources.
Build #184364 2019-09-09T18:16:23.189533+00:00
# rustc version
rustc 1.39.0-nightly (618768492 2019-09-05)
# docs.rs version
cratesfyi 0.6.0 (ff27e25 2019-09-09)

# build log
Updating crates.io index
Fresh semver-parser v0.7.0
Fresh unicode-xid v0.2.0
Fresh futures-core-preview v0.3.0-alpha.18
Fresh cfg-if v0.1.9
Fresh pin-utils v0.1.0-alpha.4
Fresh spin v0.5.2
Fresh slab v0.4.2
Fresh smallvec v0.6.10
Fresh scopeguard v1.0.0
Fresh fnv v1.0.6
Fresh arc-swap v0.4.2
Fresh semver v0.9.0
Checking futures-channel-preview v0.3.0-alpha.18
Fresh futures-sink-preview v0.3.0-alpha.18
Fresh lazy_static v1.4.0
Fresh lock_api v0.3.1
Running `rustc --edition=2018 --crate-name futures_channel /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-channel-preview-0.3.0-alpha.18/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 --cfg 'feature="alloc"' --cfg 'feature="std"' -C metadata=71a20c6869c6f414 -C extra-filename=-71a20c6869c6f414 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --cap-lints allow`
Fresh rustc_version v0.2.3
Fresh proc-macro2 v1.0.1
Fresh libc v0.2.62
Fresh byteorder v1.3.2
Fresh log v0.4.8
Fresh crossbeam-utils v0.6.6
Checking tracing-core v0.1.5
Fresh quote v1.0.2
Fresh iovec v0.1.2
Running `rustc --edition=2018 --crate-name tracing_core /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-core-0.1.5/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 --cfg 'feature="std"' -C metadata=308859e4a7f40998 -C extra-filename=-308859e4a7f40998 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern lazy_static=/home/cratesfyi/cratesfyi/debug/deps/liblazy_static-f715062325c32245.rmeta --extern spin=/home/cratesfyi/cratesfyi/debug/deps/libspin-56b20022625377b3.rmeta --cap-lints allow`
Fresh net2 v0.2.33
Fresh num_cpus v1.10.1
Fresh signal-hook-registry v1.1.1
Fresh crossbeam-queue v0.1.2
Compiling syn v1.0.5
Fresh bytes v0.4.12
Running `rustc --edition=2018 --crate-name syn /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/syn-1.0.5/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata,link -C debuginfo=2 --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"' --cfg 'feature="quote"' -C metadata=98f7653cc5cf67e9 -C extra-filename=-98f7653cc5cf67e9 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern proc_macro2=/home/cratesfyi/cratesfyi/debug/deps/libproc_macro2-2c0eb5c1817a4215.rlib --extern quote=/home/cratesfyi/cratesfyi/debug/deps/libquote-c27020d2eef8c65f.rlib --extern unicode_xid=/home/cratesfyi/cratesfyi/debug/deps/libunicode_xid-52a35864d6b546e1.rlib --cap-lints allow`
Fresh mio v0.6.19
Fresh parking_lot_core v0.6.2
Checking tokio-io v0.2.0-alpha.4
Running `rustc --edition=2018 --crate-name tokio_io /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-io-0.2.0-alpha.4/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=f2843a50a89bf1f3 -C extra-filename=-f2843a50a89bf1f3 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern bytes=/home/cratesfyi/cratesfyi/debug/deps/libbytes-edf8a12e791f4380.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern log=/home/cratesfyi/cratesfyi/debug/deps/liblog-5a40419f7cfb1be5.rmeta --cap-lints allow`
Fresh mio-uds v0.6.7
Fresh parking_lot v0.9.0
Checking tokio-codec v0.2.0-alpha.4
Running `rustc --edition=2018 --crate-name tokio_codec /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-codec-0.2.0-alpha.4/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=0c881d620d717aa0 -C extra-filename=-0c881d620d717aa0 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern bytes=/home/cratesfyi/cratesfyi/debug/deps/libbytes-edf8a12e791f4380.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern futures_sink=/home/cratesfyi/cratesfyi/debug/deps/libfutures_sink-0dfd67d934622326.rmeta --extern log=/home/cratesfyi/cratesfyi/debug/deps/liblog-5a40419f7cfb1be5.rmeta --extern tokio_io=/home/cratesfyi/cratesfyi/debug/deps/libtokio_io-f2843a50a89bf1f3.rmeta --cap-lints allow`
Checking futures-util-preview v0.3.0-alpha.18
Running `rustc --edition=2018 --crate-name futures_util /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-preview-0.3.0-alpha.18/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 --cfg 'feature="alloc"' --cfg 'feature="channel"' --cfg 'feature="default"' --cfg 'feature="futures-channel-preview"' --cfg 'feature="slab"' --cfg 'feature="std"' -C metadata=c371d37fb08b2bfe -C extra-filename=-c371d37fb08b2bfe --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern futures_channel=/home/cratesfyi/cratesfyi/debug/deps/libfutures_channel-71a20c6869c6f414.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern pin_utils=/home/cratesfyi/cratesfyi/debug/deps/libpin_utils-f996fae858c22114.rmeta --extern slab=/home/cratesfyi/cratesfyi/debug/deps/libslab-8f0f3270aa5adebc.rmeta --cap-lints allow`
Checking tokio-sync v0.2.0-alpha.4
Running `rustc --edition=2018 --crate-name tokio_sync /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-sync-0.2.0-alpha.4/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 -C metadata=7c8dfe6969831e75 -C extra-filename=-7c8dfe6969831e75 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern fnv=/home/cratesfyi/cratesfyi/debug/deps/libfnv-73263da421a634ad.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern futures_util=/home/cratesfyi/cratesfyi/debug/deps/libfutures_util-c371d37fb08b2bfe.rmeta --cap-lints allow`
Checking tokio-executor v0.2.0-alpha.4
Running `rustc --edition=2018 --crate-name tokio_executor /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-executor-0.2.0-alpha.4/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 --cfg 'feature="blocking"' --cfg 'feature="lazy_static"' --cfg 'feature="tokio-sync"' -C metadata=5148a6f23d7fbd25 -C extra-filename=-5148a6f23d7fbd25 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern futures_util=/home/cratesfyi/cratesfyi/debug/deps/libfutures_util-c371d37fb08b2bfe.rmeta --extern lazy_static=/home/cratesfyi/cratesfyi/debug/deps/liblazy_static-f715062325c32245.rmeta --extern tokio_sync=/home/cratesfyi/cratesfyi/debug/deps/libtokio_sync-7c8dfe6969831e75.rmeta --cap-lints allow`
Compiling tracing-attributes v0.1.2
Running `rustc --edition=2018 --crate-name tracing_attributes /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-attributes-0.1.2/src/lib.rs --color never --crate-type proc-macro --emit=dep-info,link -C prefer-dynamic -C debuginfo=2 -C metadata=69d931de0be7f05a -C extra-filename=-69d931de0be7f05a --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern quote=/home/cratesfyi/cratesfyi/debug/deps/libquote-c27020d2eef8c65f.rlib --extern syn=/home/cratesfyi/cratesfyi/debug/deps/libsyn-98f7653cc5cf67e9.rlib --cap-lints allow`
Checking tracing v0.1.6
Running `rustc --edition=2018 --crate-name tracing /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tracing-0.1.6/src/lib.rs --color never --crate-type lib --emit=dep-info,metadata -C debuginfo=2 --cfg 'feature="default"' --cfg 'feature="log"' --cfg 'feature="std"' -C metadata=ea9da970477411c9 -C extra-filename=-ea9da970477411c9 --out-dir /home/cratesfyi/cratesfyi/debug/deps -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern cfg_if=/home/cratesfyi/cratesfyi/debug/deps/libcfg_if-298ec937d99da0ea.rmeta --extern log=/home/cratesfyi/cratesfyi/debug/deps/liblog-5a40419f7cfb1be5.rmeta --extern spin=/home/cratesfyi/cratesfyi/debug/deps/libspin-56b20022625377b3.rmeta --extern tracing_attributes=/home/cratesfyi/cratesfyi/debug/deps/libtracing_attributes-69d931de0be7f05a.so --extern tracing_core=/home/cratesfyi/cratesfyi/debug/deps/libtracing_core-308859e4a7f40998.rmeta --cap-lints allow`
Documenting tokio-net v0.2.0-alpha.4
Running `rustdoc --edition=2018 --crate-name tokio_net /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-net-0.2.0-alpha.4/src/lib.rs --cap-lints allow --color never -o /home/cratesfyi/cratesfyi/doc --cfg 'feature="async-traits"' --cfg 'feature="bytes"' --cfg 'feature="crossbeam-queue"' --cfg 'feature="futures-sink-preview"' --cfg 'feature="iovec"' --cfg 'feature="libc"' --cfg 'feature="log"' --cfg 'feature="mio-named-pipes"' --cfg 'feature="mio-uds"' --cfg 'feature="process"' --cfg 'feature="signal"' --cfg 'feature="signal-hook-registry"' --cfg 'feature="tcp"' --cfg 'feature="tracing"' --cfg 'feature="udp"' --cfg 'feature="uds"' --cfg 'feature="winapi"' -Z unstable-options --resource-suffix -20190905-1.39.0-nightly-618768492 --static-root-path / --disable-per-crate-search --extern-html-root-url 'bytes=https://docs.rs/bytes/0.4.12' --extern-html-root-url 'crossbeam_queue=https://docs.rs/crossbeam-queue/0.1.2' --extern-html-root-url 'crossbeam_utils=https://docs.rs/crossbeam-utils/0.6.6' --extern-html-root-url 'futures_core_preview=https://docs.rs/futures-core-preview/0.3.0-alpha.18' --extern-html-root-url 'futures_sink_preview=https://docs.rs/futures-sink-preview/0.3.0-alpha.18' --extern-html-root-url 'futures_util_preview=https://docs.rs/futures-util-preview/0.3.0-alpha.18' --extern-html-root-url 'iovec=https://docs.rs/iovec/0.1.2' --extern-html-root-url 'lazy_static=https://docs.rs/lazy_static/1.4.0' --extern-html-root-url 'libc=https://docs.rs/libc/0.2.62' --extern-html-root-url 'mio=https://docs.rs/mio/0.6.19' --extern-html-root-url 'mio_named_pipes=https://docs.rs/mio-named-pipes/0.1.6' --extern-html-root-url 'mio_uds=https://docs.rs/mio-uds/0.6.7' --extern-html-root-url 'num_cpus=https://docs.rs/num_cpus/1.10.1' --extern-html-root-url 'parking_lot=https://docs.rs/parking_lot/0.9.0' --extern-html-root-url 'signal_hook_registry=https://docs.rs/signal-hook-registry/1.1.1' --extern-html-root-url 'slab=https://docs.rs/slab/0.4.2' --extern-html-root-url 'tokio_codec=https://docs.rs/tokio-codec/0.2.0-alpha.4' --extern-html-root-url 'tokio_executor=https://docs.rs/tokio-executor/0.2.0-alpha.4' --extern-html-root-url 'tokio_io=https://docs.rs/tokio-io/0.2.0-alpha.4' --extern-html-root-url 'tokio_sync=https://docs.rs/tokio-sync/0.2.0-alpha.4' --extern-html-root-url 'tracing=https://docs.rs/tracing/0.1.8' --extern-html-root-url 'winapi=https://docs.rs/winapi/0.3.8' -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern bytes=/home/cratesfyi/cratesfyi/debug/deps/libbytes-edf8a12e791f4380.rmeta --extern crossbeam_queue=/home/cratesfyi/cratesfyi/debug/deps/libcrossbeam_queue-353751bb53ca7102.rmeta --extern crossbeam_utils=/home/cratesfyi/cratesfyi/debug/deps/libcrossbeam_utils-991a0b8c8e253a78.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern futures_sink=/home/cratesfyi/cratesfyi/debug/deps/libfutures_sink-0dfd67d934622326.rmeta --extern futures_util=/home/cratesfyi/cratesfyi/debug/deps/libfutures_util-c371d37fb08b2bfe.rmeta --extern iovec=/home/cratesfyi/cratesfyi/debug/deps/libiovec-f78873b013963bcb.rmeta --extern lazy_static=/home/cratesfyi/cratesfyi/debug/deps/liblazy_static-f715062325c32245.rmeta --extern libc=/home/cratesfyi/cratesfyi/debug/deps/liblibc-7a43c6de6102fb90.rmeta --extern mio=/home/cratesfyi/cratesfyi/debug/deps/libmio-24aebd4d868c2f3f.rmeta --extern mio_uds=/home/cratesfyi/cratesfyi/debug/deps/libmio_uds-2aa0d44fc66b43a4.rmeta --extern num_cpus=/home/cratesfyi/cratesfyi/debug/deps/libnum_cpus-fefe377dc33c0a0d.rmeta --extern parking_lot=/home/cratesfyi/cratesfyi/debug/deps/libparking_lot-98f875495af1a56a.rmeta --extern signal_hook_registry=/home/cratesfyi/cratesfyi/debug/deps/libsignal_hook_registry-725e6e6955dd7bf4.rmeta --extern slab=/home/cratesfyi/cratesfyi/debug/deps/libslab-8f0f3270aa5adebc.rmeta --extern tokio_codec=/home/cratesfyi/cratesfyi/debug/deps/libtokio_codec-0c881d620d717aa0.rmeta --extern tokio_executor=/home/cratesfyi/cratesfyi/debug/deps/libtokio_executor-5148a6f23d7fbd25.rmeta --extern tokio_io=/home/cratesfyi/cratesfyi/debug/deps/libtokio_io-f2843a50a89bf1f3.rmeta --extern tokio_sync=/home/cratesfyi/cratesfyi/debug/deps/libtokio_sync-7c8dfe6969831e75.rmeta --extern tracing=/home/cratesfyi/cratesfyi/debug/deps/libtracing-ea9da970477411c9.rmeta`
error[E0432]: unresolved import `tokio_io::AsyncReadExt`
--> /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-net-0.2.0-alpha.4/src/process/mod.rs:124:27
|
124 | use tokio_io::{AsyncRead, AsyncReadExt, AsyncWrite};
|                           ^^^^^^^^^^^^
|                           |
|                           no `AsyncReadExt` in the root
|                           help: a similar name exists in the module: `AsyncRead`

error: Compilation failed, aborting rustdoc

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0432`.
thread 'main' panicked at 'ProcessError { desc: "process didn\'t exit successfully: `rustdoc --edition=2018 --crate-name tokio_net /home/cratesfyi/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-net-0.2.0-alpha.4/src/lib.rs --cap-lints allow --color never -o /home/cratesfyi/cratesfyi/doc --cfg \'feature=\"async-traits\"\' --cfg \'feature=\"bytes\"\' --cfg \'feature=\"crossbeam-queue\"\' --cfg \'feature=\"futures-sink-preview\"\' --cfg \'feature=\"iovec\"\' --cfg \'feature=\"libc\"\' --cfg \'feature=\"log\"\' --cfg \'feature=\"mio-named-pipes\"\' --cfg \'feature=\"mio-uds\"\' --cfg \'feature=\"process\"\' --cfg \'feature=\"signal\"\' --cfg \'feature=\"signal-hook-registry\"\' --cfg \'feature=\"tcp\"\' --cfg \'feature=\"tracing\"\' --cfg \'feature=\"udp\"\' --cfg \'feature=\"uds\"\' --cfg \'feature=\"winapi\"\' -Z unstable-options --resource-suffix -20190905-1.39.0-nightly-618768492 --static-root-path / --disable-per-crate-search --extern-html-root-url \'bytes=https://docs.rs/bytes/0.4.12\' --extern-html-root-url \'crossbeam_queue=https://docs.rs/crossbeam-queue/0.1.2\' --extern-html-root-url \'crossbeam_utils=https://docs.rs/crossbeam-utils/0.6.6\' --extern-html-root-url \'futures_core_preview=https://docs.rs/futures-core-preview/0.3.0-alpha.18\' --extern-html-root-url \'futures_sink_preview=https://docs.rs/futures-sink-preview/0.3.0-alpha.18\' --extern-html-root-url \'futures_util_preview=https://docs.rs/futures-util-preview/0.3.0-alpha.18\' --extern-html-root-url \'iovec=https://docs.rs/iovec/0.1.2\' --extern-html-root-url \'lazy_static=https://docs.rs/lazy_static/1.4.0\' --extern-html-root-url \'libc=https://docs.rs/libc/0.2.62\' --extern-html-root-url \'mio=https://docs.rs/mio/0.6.19\' --extern-html-root-url \'mio_named_pipes=https://docs.rs/mio-named-pipes/0.1.6\' --extern-html-root-url \'mio_uds=https://docs.rs/mio-uds/0.6.7\' --extern-html-root-url \'num_cpus=https://docs.rs/num_cpus/1.10.1\' --extern-html-root-url \'parking_lot=https://docs.rs/parking_lot/0.9.0\' --extern-html-root-url \'signal_hook_registry=https://docs.rs/signal-hook-registry/1.1.1\' --extern-html-root-url \'slab=https://docs.rs/slab/0.4.2\' --extern-html-root-url \'tokio_codec=https://docs.rs/tokio-codec/0.2.0-alpha.4\' --extern-html-root-url \'tokio_executor=https://docs.rs/tokio-executor/0.2.0-alpha.4\' --extern-html-root-url \'tokio_io=https://docs.rs/tokio-io/0.2.0-alpha.4\' --extern-html-root-url \'tokio_sync=https://docs.rs/tokio-sync/0.2.0-alpha.4\' --extern-html-root-url \'tracing=https://docs.rs/tracing/0.1.8\' --extern-html-root-url \'winapi=https://docs.rs/winapi/0.3.8\' -L dependency=/home/cratesfyi/cratesfyi/debug/deps --extern bytes=/home/cratesfyi/cratesfyi/debug/deps/libbytes-edf8a12e791f4380.rmeta --extern crossbeam_queue=/home/cratesfyi/cratesfyi/debug/deps/libcrossbeam_queue-353751bb53ca7102.rmeta --extern crossbeam_utils=/home/cratesfyi/cratesfyi/debug/deps/libcrossbeam_utils-991a0b8c8e253a78.rmeta --extern futures_core=/home/cratesfyi/cratesfyi/debug/deps/libfutures_core-1879401bab767288.rmeta --extern futures_sink=/home/cratesfyi/cratesfyi/debug/deps/libfutures_sink-0dfd67d934622326.rmeta --extern futures_util=/home/cratesfyi/cratesfyi/debug/deps/libfutures_util-c371d37fb08b2bfe.rmeta --extern iovec=/home/cratesfyi/cratesfyi/debug/deps/libiovec-f78873b013963bcb.rmeta --extern lazy_static=/home/cratesfyi/cratesfyi/debug/deps/liblazy_static-f715062325c32245.rmeta --extern libc=/home/cratesfyi/cratesfyi/debug/deps/liblibc-7a43c6de6102fb90.rmeta --extern mio=/home/cratesfyi/cratesfyi/debug/deps/libmio-24aebd4d868c2f3f.rmeta --extern mio_uds=/home/cratesfyi/cratesfyi/debug/deps/libmio_uds-2aa0d44fc66b43a4.rmeta --extern num_cpus=/home/cratesfyi/cratesfyi/debug/deps/libnum_cpus-fefe377dc33c0a0d.rmeta --extern parking_lot=/home/cratesfyi/cratesfyi/debug/deps/libparking_lot-98f875495af1a56a.rmeta --extern signal_hook_registry=/home/cratesfyi/cratesfyi/debug/deps/libsignal_hook_registry-725e6e6955dd7bf4.rmeta --extern slab=/home/cratesfyi/cratesfyi/debug/deps/libslab-8f0f3270aa5adebc.rmeta --extern tokio_codec=/home/cratesfyi/cratesfyi/debug/deps/libtokio_codec-0c881d620d717aa0.rmeta --extern tokio_executor=/home/cratesfyi/cratesfyi/debug/deps/libtokio_executor-5148a6f23d7fbd25.rmeta --extern tokio_io=/home/cratesfyi/cratesfyi/debug/deps/libtokio_io-f2843a50a89bf1f3.rmeta --extern tokio_sync=/home/cratesfyi/cratesfyi/debug/deps/libtokio_sync-7c8dfe6969831e75.rmeta --extern tracing=/home/cratesfyi/cratesfyi/debug/deps/libtracing-ea9da970477411c9.rmeta` (exit code: 1)", exit: Some(ExitStatus(ExitStatus(256))), output: None }

Could not document `tokio-net`.', src/bin/cratesfyi.rs:161:13
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.