r-rserve 1.8-6 should compile a binary "RServ" which would be made available for execution similar to "R"
It think it fails because it wants to save the binary to /gnu/store where the package "r-minimal" is installed.
It might be also that r-minimal has to be installed with "
"--enable-R-shlib"
In gn/packages/statistics.scm there is "r-with-tests". Unfortunately it is not a public package, so I cannot install it easily
RServ is quite important: any interop with R (on multiple languages) goes via this socket-server.