@jbeezley string could not be split as you set it up (with \) so I tweaked it a bit. I like how you test if path actually exist before setting to a PATH
Ok need to replace ; with actuall space so you dont have to have space at end of paths
replace ; with space doesnt work in cmake adding a space by hand, not perfect but works
@jbeezley you didn't have 's' at the end of ExternalS that made openmpi fail (and would make R_HOME fail too), fixed