Compilation ERROR

Summary:

I am starting to use Stan interface for R but have a compilation error

Description:

I installed Rtools on my C:/ drive and followed all the steps described here: https://github.com/stan-dev/rstan/wiki/Installing-RStan-on-Windows

Reproducible Steps:

> Sys.getenv('PATH')
[1] "C:\Program Files\R\R-3.5.1\bin\x64;c:\Rtools\bin;c:\Rtools\mingw_64\bin;"

> system('g++ -v')
Using built-in specs.
COLLECT_GCC=c:\Rtools\mingw_64\bin\G__~1.EXE
COLLECT_LTO_WRAPPER=c:/Rtools/mingw_64/bin/../libexec/gcc/x86_64-w64-mingw32/4.9.3/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-4.9.3/configure --host=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64 --with-sysroot=/home/Jeroen/mingw-gcc-4.9.3/x86_64-493-posix-seh-rt_v3-s/mingw64 --with-gxx-include-dir=/mingw64/x86_64-w64-mingw32/include/c++ --enable-static --disable-shared --disable-multilib --enable-languages=c,c++,fortran,lto --enable-libstdcxx-time=yes --enable-threads=posix --enable-libgomp --enable-libatomic --enable-lto --enable-graphite --enable-checking=release --enable-fully-dynamic-string --enable-version-specific-runtime-libs --disable-isl-version-check --disable-cloog-version-check --disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona --with-tune=core2 --with-libiconv --with-system-zlib --with-gmp=/home/Jeroen/mingw-gcc-4.9.3/prerequisites/x86_64-w64-mingw32-static --with-m...
Thread model: posix
gcc version 4.9.3 (x86_64-posix-seh, Built by MinGW-W64 project)

> system('where make')
c:\Rtools\bin\make.exe

Current Output:

And I get this error message at the last step:
fx <- inline::cxxfunction( signature(x = "integer", y = "numeric" ) , '
return ScalarReal( INTEGER(x)[0] * REAL(y)[0] ) ;
' )
Error in compileCode(f, code, language = language, verbose = verbose) :
Compilation ERROR, function(s)/method(s) not created! C:/Rtools/mingw_64/bin/../lib/gcc/x86_64-w64-mingw32/4.9.3/../../../../x86_64-w64-mingw32/bin/ld.exe: cannot find -lStanHeaders
collect2.exe: error: ld returned 1 exit status

> fx( 2L, 5 )
Error in .Primitive(".Call")(<pointer: (nil)>, x, y) :
NULL value passed as symbol address

RStan Version:

‘2.17.3’

R Version:

R version 3.5.1 (2018-07-02)

Operating System:

64 bit

No source files or tests are named; start with the Windows installation guide, the reported PATH and Rtools commands, and the inline::cxxfunction reproduction. Trace why the linker cannot find -lStanHeaders and verify the same example compiles and runs successfully without the NULL symbol-address error.