Assuming you're talking about the MoSync SDK comprising Eclipse, as far I am aware, there isn't currently (as of May 2013) an official means of building the SDK on Linux, regardless of what the (now-outdated) official MoSync-on-Linux post used to suggest.
I posed a similar question regarding a Linux/Ubuntu build myself, posting as 'sixman9', in the following MoSync forum thread:
What is missing from a fully functioning Linux version of MoSync dev tools - Please outline the issues?
I got plenty of help regarding building MoSync on Ubuntu, Fredrik Eldh appears to be the Guru regarding the issues surrounding a Linux port (and has submitted code updates), another user, 'sudurais' got the MoSync SDK built for Ubuntu, and shares the steps he took within the thread.
Having coaxed this information out of them, I was in the process of writing a definitive bash build script, the start(s) of which are outlined in the forum post. However, I'm currently side-tracked with 'Life' (Baby/House move), so my involvement is on hold, at least for the time-being.
I hope this info helps you.