CMake/MinGW unknown compilers, gcc.exe broken

Question

I am trying to install on my windows desktop, a software suite called NUPACK which is used to design nucleic acid reaction pathways. http://www.nupack.org/

This software requires CMake to install, and from my understanding, CMake does not have compilers by itself, and requires us to have compilers separately installed. As such, I downloaded MinGW to use as a C++ compiler. Prior to running, I have set the environment variables of both CMake and MinGW's bin. I am running CMake (version 3.11.1) through the command prompt but I keep encountering the following problem:

C:\Users\Nicholas\Documents\nupack\build>Cmake -DCMAKE_INSTALL_PREFIX=NUPACKINSTALL -G "MinGW Makefiles" ..
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
-- Check for working C compiler: C:/MinGW/bin/gcc.exe
-- Check for working C compiler: C:/MinGW/bin/gcc.exe -- broken
CMake Error at C:/Program Files/CMake/share/cmake- 
3.11/Modules/CMakeTestCCompiler.cmake:52 (message):
  The C compiler

    "C:/MinGW/bin/gcc.exe"

  is not able to compile a simple test program.

I'm guessing CMake cannot identify my MinGW gcc and gcc++ compilers somehow. I tried the following next, but the same error arose.

set CMAKE_C_COMPILER=%C:\mingw\bin\gcc%
set CMAKE_CXX_COMPILER=%C:\mingw\bin\g++%

Has anyone encountered the same problem? Can this be resolved by using MinGW64? I am using Windows 10 and previously, I tried using visual studio 2017's compilers, but it had its on set of problems too.

Answer 1

Yes, the problem is that CMake cannot find GCC compiler. Before be sure that g++ and gcc are installed. It can be MinGW64 or Cygwin.

There are at least three ways to link GCC compiler.

1st way:

Set compilers in CMakeLists.txt:

set(CMAKE_C_COMPILER C:\path\to\gcc.exe)
set(CMAKE_CXX_COMPILER C:\path\to\g++.exe)

2nd way:

When calling cmake in terminal or cmd:

cmake -DCMAKE_C_COMPILER="C:\path\to\gcc.exe" -DCMAKE_CXX_COMPILER="C:\path\to\g++.exe"

3rd way:

Set as environment variable: Go to Windows "Environment Variables" and add to PATH this:

;C:\path_to_MinGW_or_Cygwin\bin