`make docs` fails if configured with `--disable-rpath`

[gifnksm]

make docs fails with the following error.

$ ./configure --disable-rpath
...
$ make
...
$ make docs                                                                                                           (git)-[master]
cfg: build triple x86_64-unknown-linux-gnu
cfg: host triples x86_64-unknown-linux-gnu
cfg: target triples x86_64-unknown-linux-gnu i686-unknown-linux-gnu
cfg: non-build target triples i686-unknown-linux-gnu
cfg: enabling more debugging (CFG_ENABLE_DEBUG)
cfg: host for x86_64-unknown-linux-gnu is x86_64
cfg: host for i686-unknown-linux-gnu is i386
cfg: os for x86_64-unknown-linux-gnu is unknown-linux-gnu
cfg: os for i686-unknown-linux-gnu is unknown-linux-gnu
cfg: using gcc
cfg: no llnextgen found, omitting grammar-verification
version-info: doc/version_info.html
sed -e "s/VERSION/0.10-pre/; s/SHORT_HASH/cc6afe1e/;\
                s/STAMP/cc6afe1ec0d3e5e9da4c0f7d0443991afe74dfaf/;" /home/nksm/pkg/rust/src/rust/doc/version_info.html.template >doc/version_info.html
pandoc: doc/rust.html
version-stamp: doc/version.md
pandoc: doc/rust.tex
pandoc: doc/rustpkg.html
pandoc: doc/rustdoc.html
pandoc: doc/tutorial.html
pandoc: doc/tutorial.tex
pandoc: doc/index.html
pandoc: doc/complement-lang-faq.html
pandoc: doc/complement-project-faq.html
pandoc: doc/complement-usage-faq.html
pandoc: doc/complement-cheatsheet.html
pandoc: doc/complement-bugreport.html
pandoc: doc/guide-macros.html
pandoc: doc/guide-container.html
pandoc: doc/guide-ffi.html
pandoc: doc/guide-testing.html
pandoc: doc/guide-lifetimes.html
pandoc: doc/guide-tasks.html
pandoc: doc/guide-conditions.html
pandoc: doc/guide-rustpkg.html
pandoc: doc/guide-pointers.html
pandoc: doc/guide-runtime.html
pdflatex: doc/rust.pdf
This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Arch Linux)
 restricted \write18 enabled.
entering extended mode
pdflatex: doc/tutorial.pdf
This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Arch Linux)
 restricted \write18 enabled.
entering extended mode
rustdoc: doc/std/index.html
x86_64-unknown-linux-gnu/stage2/bin/rustdoc: symbol lookup error: x86_64-unknown-linux-gnu/stage2/bin/rustdoc: undefined symbol: _ZN4uvio8new_loop19hba9988a53566c07fao9v0.10.preE
/home/nksm/pkg/rust/src/rust/mk/docs.mk:308: recipe for target 'doc/std/index.html' failed
make: *** [doc/std/index.html] Error 127