Cargo doc fails on nightly #582

humbug@home:~/tokio$ cargo doc
 Documenting tokio-reactor v0.1.2 (file:///home/humbug/tokio/tokio-reactor)                                                                                                
 Documenting tokio-threadpool v0.1.5 (file:///home/humbug/tokio/tokio-threadpool)
    Checking tokio-fs v0.1.2 (file:///home/humbug/tokio/tokio-fs)
error: `[clear_write_ready]` cannot be resolved, ignoring it...
  --> tokio-reactor/src/poll_evented.rs:50:6
   |
50 | /// [`clear_write_ready`]. This clears the readiness state until a new readiness
   |      ^^^^^^^^^^^^^^^^^^^ cannot be resolved, ignoring
   |
note: lint level defined here
  --> tokio-reactor/src/lib.rs:31:23
   |
31 | #![deny(missing_docs, warnings, missing_debug_implementations)]
   |                       ^^^^^^^^
   = note: #[deny(intra_doc_link_resolution_failure)] implied by #[deny(warnings)]
   = help: to escape `[` and `]` characters, just add '\' before them like `\[` or `\]`

error: Could not document `tokio-reactor`.

Caused by:
  process didn't exit successfully: `rustdoc --crate-name tokio_reactor tokio-reactor/src/lib.rs -o /home/humbug/tokio/target/doc -L dependency=/home/humbug/tokio/target/debug/deps --extern futures=/home/humbug/tokio/target/debug/deps/libfutures-4b1934908439a98f.rmeta --extern log=/home/humbug/tokio/target/debug/deps/liblog-ee3b87571c62e0bd.rmeta --extern mio=/home/humbug/tokio/target/debug/deps/libmio-2aead9b7ec435e33.rmeta --extern slab=/home/humbug/tokio/target/debug/deps/libslab-6bd047cac0599ec2.rmeta --extern tokio_executor=/home/humbug/tokio/target/debug/deps/libtokio_executor-c2e04cd785ac0346.rmeta --extern tokio_io=/home/humbug/tokio/target/debug/deps/libtokio_io-9ae3a9fb125ba40c.rmeta` (exit code: 1)
warning: build failed, waiting for other jobs to finish...
error: `[FromEntropy::from_entropy]` cannot be resolved, ignoring it...
   --> /home/humbug/.cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.5.4/src/lib.rs:163:8
    |
163 | //! [`FromEntropy::from_entropy`], and notably in [`thread_rng`]. Except by
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot be resolved, ignoring
    |
note: lint level defined here
   --> tokio-threadpool/src/lib.rs:2:9
    |
2   | #![deny(warnings, missing_docs, missing_debug_implementations)]
    |         ^^^^^^^^
    = note: #[deny(intra_doc_link_resolution_failure)] implied by #[deny(warnings)]
    = help: to escape `[` and `]` characters, just add '\' before them like `\[` or `\]`

error: `[thread_rng]` cannot be resolved, ignoring it...
   --> /home/humbug/.cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.5.4/src/lib.rs:163:54
    |
163 | //! [`FromEntropy::from_entropy`], and notably in [`thread_rng`]. Except by
    |                                                      ^^^^^^^^^^^^ cannot be resolved, ignoring
    |
    = help: to escape `[` and `]` characters, just add '\' before them like `\[` or `\]`

error: Could not document `tokio-threadpool`.

Caused by:
  process didn't exit successfully: `rustdoc --crate-name tokio_threadpool tokio-threadpool/src/lib.rs -o /home/humbug/tokio/target/doc -L dependency=/home/humbug/tokio/target/debug/deps --extern crossbeam_deque=/home/humbug/tokio/target/debug/deps/libcrossbeam_deque-691cf374a0d3b12d.rmeta --extern crossbeam_utils=/home/humbug/tokio/target/debug/deps/libcrossbeam_utils-7bb89505998d0717.rmeta --extern futures=/home/humbug/tokio/target/debug/deps/libfutures-4b1934908439a98f.rmeta --extern log=/home/humbug/tokio/target/debug/deps/liblog-ee3b87571c62e0bd.rmeta --extern num_cpus=/home/humbug/tokio/target/debug/deps/libnum_cpus-07b4fda9e10ff6f1.rmeta --extern rand=/home/humbug/tokio/target/debug/deps/librand-0d53f3e365b5a6a7.rmeta --extern tokio_executor=/home/humbug/tokio/target/debug/deps/libtokio_executor-c2e04cd785ac0346.rmeta` (exit code: 1)

humbug@home:~/tokio$ git log -n1
commit 0490280d662f000aff674593cc9a4f69a1cd1171

humbug@home:~/tokio$ grep rand Cargo.lock 
name = "rand"
name = "rand"
 "rand_core 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
name = "rand_core"
 "rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
"checksum rand 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "eba5f8cb59cc50ed56be8880a5c7b496bfd9bd26394e176bc67884094145c2c5"
"checksum rand 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)" = "12397506224b2f93e6664ffc4f664b29be8208e5157d3d90b44f09b5fae470ea"
"checksum rand_core 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "edecf0f94da5551fc9b492093e30b041a891657db7940ee221f9d2f66e82eef2"