$ brew install libyaml
==> Downloading http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz
Already downloaded: /Library/Caches/Homebrew/libyaml-0.1.4.tar.gz
==> ./configure --prefix=/usr/local/Cellar/libyaml/0.1.4
==> make install
Warning: Could not link libyaml. Unlinking...
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
You can try again using `brew link libyaml'
==> Summary
/usr/local/Cellar/libyaml/0.1.4: 7 files, 336K, built in 9 seconds
OS X 10.8.2如何解决这个问题？我该怎么办 ？