Got pretty far along but at the end I got these messages after the cmake command:
CMake Error at src/cpp/desktop/CMakeLists.txt:18 (cmake_policy):
Policy "CMP0020" is not known to this version of CMake.
CMake Error at src/cpp/desktop/CMakeLists.txt:69 (get_filename_component):
get_filename_component called with incorrect number of arguments
CMake Error at src/cpp/desktop/CMakeLists.txt:76 (find_package):
By not providing "FindQt5Core.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "Qt5Core", but
CMake did not find one.
Could not find a package configuration file provided by "Qt5Core" with any
of the following names:
Add the installation prefix of "Qt5Core" to CMAKE_PREFIX_PATH or set
"Qt5Core_DIR" to a directory containing one of the above files. If
"Qt5Core" provides a separate development package or SDK, be sure it has
-- Configuring incomplete, errors occurred!
:~/rstudio/build# make install
make: *** No rule to make target 'install'. Stop.