Building Packages for Yoper is so easy and safe that it does not affect the normal working system.
Though it may be a little hard to get to know what exactly Mach is, once you see it running, you would be happy that there exists an easy way to build packages 🙂
Yes, Yoper uses the Mach environment to build packages. In simple words, Mach is just a chroot environment in which you can build the package. To explain it more detail,mach allows you to set up clean build roots from scratch for any distribution or distribution variation supported and also for each package build, mach creates from downloaded RPM’s a chroot, which is a small linux environment. Mach controls this environment and also resolves build dependency (via the hosts apt-get) to create exactly the environment required to make functional and clean packages.
The dependency list can be easily be gathered with the apt-get in mach. Refer Pre-building the Source Package in mach environment for more details.
I am not sure how far these guides can be helpful for other distros.
Any help, please feel free to post at Yoper Forums or at Yoper IRC (irc.freenode.net/#yoper)