Unable to get Stan working with R 3.5.1 and Catalina 10.15.2

[bgoodri]

OK. @wds15 says that

Dealing with Catalina II

Hi Everyone! I used the latest installer linked above, but that left me with a non-working setup for running stan models. The reasons seems to be that the tools leave you with a ~/.R/Makevars with this content: # clang: start CFLAGS=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk CCFLAGS=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk CXXFLAGS=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk CPPFLAGS=-isysroot /Library/Developer/CommandLineTools/SDKs/Ma…

if you download the installer from

Releases · coatless-mac/r-macos-rtools

CTRL+right click on the file, then clicking “Open” will get the installer going

So, try that first.