Building from source with CMake results in an error

[Progressive]

Since an installation via .exe does not work I’m trying to build ROOT from source now:

C:\ROOT\install_dir> cmake -DCMAKE_INSTALL_PREFIX=C:\ROOT\install_dir C:\Users\User\Downloads\root_v6.26.02.source\root-6.26.02
– Building for: NMake Makefiles
CMake Deprecation Warning at CMakeLists.txt:12 (cmake_policy):
The OLD behavior for policy CMP0091 will be removed from a future version
of CMake.

The cmake-policies(7) manual explains that the OLD behaviors of all
policies are deprecated and that a policy should be set to OLD only under
specific short-term circumstances. Projects should be ported to the NEW
behavior and not rely on setting a policy to OLD.

CMake Error at CMakeLists.txt:30 (project):
Running

‘nmake’ ‘-?’

failed with:

The system cannot find the file specified

CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
– Configuring incomplete, errors occurred!
See also “C:/ROOT/install_dir/CMakeFiles/CMakeOutput.log”.

C:\ROOT\install_dir>

I followed exactly Building ROOT from source - ROOT so I don’t know what’s wrong here. It seems further parameters need to be passed to the entered command but which and why isn’t it given in the instruction?

[bellenot]

@Progressive

Since an installation via .exe does not work

What doesn’t work? How does it fail?
And please take a look at the end of Installing ROOT - ROOT to see how to build from source on Windows. You should do something like this:

cmake -G"Visual Studio 16 2019" -A Win32 -Thost=x64 -DCMAKE_INSTALL_PREFIX=C:\ROOT\install_dir C:\Users\User\Downloads\root_v6.26.02.source\root-6.26.02

and then:

cmake --build . --config Release --target install

[Progressive]

thank you, though I don’t need it anymore but at least I know now what the command should look like.
At least in principle.

Is there an “easy” way to look up all those --build --config --target options?
Just for curiousity and god’s sake

[bellenot]

The build options are the ones available with Visual Studio: Debug, Release, RelWithDebInfo, and MinSizeRel. See CMAKE_BUILD_TYPE — CMake 3.23.1 Documentation