Error installing hadoop with homebrew

You have to do a brew update first. It was pointing to the wrong version, but that seems to be fixed now.

It seems that Homebrew formula for Hadoop is outdated, it points to 1.1.2 instead of 1.2.1. Until the guys from Homebrew fix the bug you can do the following steps in order to install Hadoop 1.1.2:

1. Download manually version 1.1.2 from http://archive.apache.org/dist/hadoop/core/hadoop-1.1.2/hadoop-1.1.2.tar.gz to any folder in your computer
2. Then move the file hadoop-1.1.2.tar.gz to homebrew's temporary folder, if you have not changed it before, it should be located in /Library/Caches/Homebrew

3. Finally you can install Hadoop using Homebrew, now brew will find that the file has already been downloaded and will proceed with installation as follows:

   $ brew install hadoop==> Downloading http://www.apache.org/dyn/closer.cgi?path=hadoop/core/hadoop-1.1.2/hadoop-1.1.2.tar.Already downloaded: /Library/Caches/Homebrew/hadoop-1.1.2.tar.gz==> CaveatsIn Hadoop's config file:  /usr/local/Cellar/hadoop/1.1.2/libexec/conf/hadoop-env.sh$JAVA_HOME has been set to be the output of:  /usr/libexec/java_home==> Summary  /usr/local/Cellar/hadoop/1.1.2: 271 files, 78M, built in 2 seconds