mingw -- cl is not recognized as an internal or external command -- my mingw in new and environment is true

Question

As I mentioned in the comment to your question, its looking for the Windows compiler, which you probably dont have installed. According to the SCons man page, you can fix this as follows:

MinGW

The MinGW bin directory must be in your PATH environment variable or the PATH variable under the ENV construction variable for SCons to detect and use the MinGW tools. When running under the native Windows Python interpreter, SCons will prefer the MinGW tools over the Cygwin tools, if they are both installed, regardless of the order of the bin directories in the PATH variable. If you have both MSVC and MinGW installed and you want to use MinGW instead of MSVC, then you must explictly tell SCons to use MinGW by passing

tools=['mingw']

to the Environment() function, because SCons will prefer the MSVC tools over the MinGW tools.

So, change the instantiation of your Environment to something like this:

env = Environment(tools=['mingw'])

If you need to specify more in the Environment constructor, you can do something like this:

env = Environment(tools=['mingw'], variables = command_line_vars)