As of this writing, mosh in EPEL is broken in terms of install on Amazon Linux (2013-03). However, that doesn't mean you can't just build it manually.
First, you will need git:
sudo yum install git
Open /etc/yum.repos.d/epel.repo and change enabled=0 to enabled=1 in the [epel] section.
Install all the dependencies necessary to build mosh:
sudo yum install protobuf-compiler protobuf-devel libutempter-devel \ ncurses ncurses-devel zlib-devel autoconf automake openssl-devel \ gcc gcc-c++
First you need to clone the mosh source using git. We'll do all our work in /var/tmp:
cd /var/tmp git clone https://github.com/keithw/mosh.git cd mosh
You should now be in /var/tmp/mosh, or whatever directory you cloned mosh into. Run the following commands:
./autogen.sh ./configure make sudo make install
You should be all set now. Note that unless you change configure options, mosh will be installed in /usr/local/bin by default. You can change that with the standard –prefix option.
If you run into any errors, please let me know via email at admin at splitstreams dot com.