http://people.redhat.com/sgrubb/files/Rstudio/
If you are on Fedora 26 or later, you will need to install the compat-openssl-devel package.
$ dnf install compat-openssl10-devel --allowerasing
This will delete openssl-devel, but you can re-install it later after Rstudio is built. If you are building it for the first time, there are some instructions here.
So, what's new? The folks over at Rstudio blogged about some changes in the 1.1 release. The SRPM that I am providing also includes the bug fixes that are in their v1.1a preview release.