rustdoc - panicked at 'Unexpected empty destination: ["dsp"]' - occurs on beta and nightly

[mitchmindtree]

Travis is failing when running rustdoc on my dsp crate due to a panic occurring in rustdoc:

Compiling dsp-chain v0.7.1 (file:///home/travis/build/RustAudio/dsp-chain)
     Running `rustdoc src/lib.rs --crate-name dsp -o /home/travis/build/RustAudio/dsp-chain/target/doc -L dependency=/home/travis/build/RustAudio/dsp-chain/target/debug -L dependency=/home/travis/build/RustAudio/dsp-chain/target/debug/deps --extern num=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libnum-397f282c1d72fe58.rlib --extern num=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libnum-397f282c1d72fe58.rlib --extern sound_stream=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libsound_stream-96ca28702c32f71d.rlib --extern sound_stream=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libsound_stream-96ca28702c32f71d.rlib --extern daggy=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libdaggy-6c8daed9a0d833d9.rlib --extern daggy=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libdaggy-6c8daed9a0d833d9.rlib`
thread '<unnamed>' panicked at 'Unexpected empty destination: ["dsp"]', ../src/librustdoc/html/render.rs:1127
Could not document `dsp-chain`.
Caused by:
  Process didn't exit successfully: `rustdoc src/lib.rs --crate-name dsp -o /home/travis/build/RustAudio/dsp-chain/target/doc -L dependency=/home/travis/build/RustAudio/dsp-chain/target/debug -L dependency=/home/travis/build/RustAudio/dsp-chain/target/debug/deps --extern num=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libnum-397f282c1d72fe58.rlib --extern num=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libnum-397f282c1d72fe58.rlib --extern sound_stream=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libsound_stream-96ca28702c32f71d.rlib --extern sound_stream=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libsound_stream-96ca28702c32f71d.rlib --extern daggy=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libdaggy-6c8daed9a0d833d9.rlib --extern daggy=/home/travis/build/RustAudio/dsp-chain/target/debug/deps/libdaggy-6c8daed9a0d833d9.rlib` (exit code: 101)
The command "cargo doc --verbose" exited with 101.

He builds fine on the stable channel, but fails with the same error on both beta and nightly channels.

The line where the panic occurs seems to be here.

Unfortunately I only have stable available to me on my personal computer atm, and I don't have time to investigate much further.

This seems to be caused by re-exporting crates, e.g:

extern crate foo;
pub use foo as bar;

Small repro project: https://github.com/Eljay/issue-28927
The regression from stable seems to be caused by #27643.

[mitchmindtree]

I'm still getting this same error on the current stable build of rust.

Here's the backtrace:

mindTree:dsp-chain Mitch$ RUST_BACKTRACE=1 cargo doc
 Documenting dsp-chain v0.10.0 (file:///Users/Mitch/Programming/Rust/dsp-chain)
thread '<unnamed>' panicked at 'Unexpected empty destination: ["dsp", "daggy"]', ../src/librustdoc/html/render.rs:1184
stack backtrace:
   1:        0x111601058 - sys::backtrace::tracing::imp::write::h06df28c2a8d245f9t9s
   2:        0x11160725f - panicking::log_panic::_<closure>::closure.39451
   3:        0x111606d02 - panicking::log_panic::h9348b1b0af36ae6aCYw
   4:        0x1115c8c86 - sys_common::unwind::begin_unwind_inner::h005d402245ebd8560cs
   5:        0x1115c962e - sys_common::unwind::begin_unwind_fmt::h440d2eb18c439fa86bs
   6:        0x10d85c166 - html::render::run::h42919733a08147f6xsn
   7:        0x10d8df047 - main_args::h9f2afc62a54ae9fbE2t
   8:        0x10d8da9f8 - sys_common::unwind::try::try_fn::try_fn::h7212718370687295260
   9:        0x1115fec08 - __rust_try
  10:        0x1115f2f8e - sys_common::unwind::try::inner_try::hcc3a84c80e36120fy9r
  11:        0x10d8daebe - boxed::_<impl>::call_box::call_box::h14966036215268722962
  12:        0x1116065ed - sys::thread::_<impl>::new::thread_start::h5776bf5f72f331a7Rvw
  13:     0x7fff889bf059 - _pthread_body
  14:     0x7fff889befd6 - _pthread_start
Could not document `dsp-chain`.

rustc 1.5.0 (3d7cd77e4 2015-12-04)

[mitchmindtree]

Ahh apologies, I see that this has been fixed in the latest nightly.