64-bit compilation broken in Windows?

I was unable to build cmdStan in 64-bit. Here is the error message:

c:\depot\cmdstan>make build
uname: not found
uname: not found
g++ -I src -I stan/src -isystem stan/lib/stan_math/ -isystem stan/lib/stan_math/lib/eigen_3.3.3 -isystem stan/lib/stan_math/lib/boost_1.62.0 -isystem stan/lib/stan_math/lib/cvodes_2.9.0/include -Wall -DEIGEN_NO_DEBUG  -DBOOST_RESULT_OF_USE_TR1 -DBOOST_NO_DECLTYPE -DBOOST_DISABLE_ASSERTS -DFUSION_MAX_VECTOR_SIZE=12 -DNO_FPRINTF_OUTPUT -pipe  -m64 -Wno-unused-function -Wno-uninitialized -Wno-unused-but-set-variable   -c -O3 -o bin/cmdstan/stanc.o src/cmdstan/stanc.cpp
Assembler messages:
src/cmdstan/stanc.cpp:1:0: sorry, unimplemented: 64-bit mode not compiled in
 #include <stan/command/stanc_helper.hpp>
Fatal error: no compiled in support for x86_64
make: *** [bin/cmdstan/stanc.o] Error 1

To overcome this, I changed to “BIT=32” in make/os_win. This seemed to work okay.

If this issue known about? If so, perhaps BIT can be set to 32 in os_win by default, until fixed. It stumped me for a bit, until I read more of the documentation.

Operating System: Windows 10
Interface Version: cmdStan 2.15
Compiler/Toolkit: make, g++, via RTools

Which RTools version are you using?

Rtools version

Just found this stack overflow thread. Perhaps the second one may help:

(sorry, debugging blind right now. I don’t have a Windows 10 machine available at the moment.)

Hopefully fixing the path with solve the issue. If that doesn’t work, we can try to figure out how your computer is configured.