iobuf 5.4.4

# rustc version
rustc 1.12.0-nightly (54c0dcfd6 2016-07-28)
# docs.rs version
cratesfyi 0.2.0 (5dbd676 2016-07-30)

# build log
thread 'rustc' panicked at 'phase_2_configure_and_expand aborted in rustdoc!: 3', ../src/libcore/result.rs:788
note: Run with `RUST_BACKTRACE=1` for a backtrace.

Updating registry `https://github.com/rust-lang/crates.io-index`
Downloading iobuf v5.4.4
Documenting iobuf v5.4.4
Running `rustdoc .cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/lib.rs --crate-name iobuf -o /home/cratesfyi/iobuf-5.4.4/doc -L dependency=/home/cratesfyi/iobuf-5.4.4/debug -L dependency=/home/cratesfyi/iobuf-5.4.4/debug/deps`
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:44:1: 44:21 error: The attribute `unsafe_destructor` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642) 
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:44 #[unsafe_destructor]
^~~~~~~~~~~~~~~~~~~~
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:44:1: 44:21 help: add #![feature(custom_attribute)] to the crate attributes to enable 
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:91:1: 91:21 error: The attribute `unsafe_destructor` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642) 
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:91 #[unsafe_destructor]
^~~~~~~~~~~~~~~~~~~~
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/impls.rs:91:1: 91:21 help: add #![feature(custom_attribute)] to the crate attributes to enable 
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/appendbuf.rs:506:1: 506:21 error: The attribute `unsafe_destructor` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642) 
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/appendbuf.rs:506 #[unsafe_destructor]
^~~~~~~~~~~~~~~~~~~~
.cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/appendbuf.rs:506:1: 506:21 help: add #![feature(custom_attribute)] to the crate attributes to enable 
error: internal compiler error: unexpected panic 
note: the compiler unexpectedly panicked. this is a bug. 
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports 
thread 'main' panicked at 'ChainedError {
error: failed to compile `iobuf v5.4.4`, intermediate artifacts can be found at `/home/cratesfyi/iobuf-5.4.4`,
cause: ChainedError {
error: Could not document `iobuf`.,
cause: Process didn't exit successfully: `rustdoc .cargo/registry/src/github.com-1ecc6299db9ec823/iobuf-5.4.4/src/lib.rs --crate-name iobuf -o /home/cratesfyi/iobuf-5.4.4/doc -L dependency=/home/cratesfyi/iobuf-5.4.4/debug -L dependency=/home/cratesfyi/iobuf-5.4.4/debug/deps` (exit code: 101)
}
}', src/bin/cratesfyi.rs:119
note: Run with `RUST_BACKTRACE=1` for a backtrace.