Q: When I ran "make install" in the Command Prompt/Terminal window following the Developer Installation Guide, I got the following error:
sh ./tools/prep
A: Please make sure that the cygwin path is put after the rtools paths (e.g., C:\rtools40\usr\bin;C:\rtools40\mingw64\bin;C:\R\R-4.0.4\bin;C:\cygwin64\bin;).
./tools/prep: line 2: $'\r': command not found
: invalid option name set: errexit
make: *** [Makefile:72: install] Error 2