This package is not installable (it should maybe require springrts-engine instead of springrts), outdated (no surprise there) and the main source (evo-v6.42.sdz) is not at the given location anymore. If there is any interest in this, I (or anyone else) could try to fix these problems. Fortunately, their new main repository on Github provides source archives.

This above situation is much worse for springrts-zero-k, which does not provide source archives and states as the official means of installing it on Linux that you should either run a "semi-portable" shell script (!) or execute a .exe file with Mono (!!). That project seems to be heading for "proprietardom" anyway, so I guess its variant here is headed for the chopping block.