NetGhost is developed with Mingw-w64 and Msys as console. It is recommend to use the same development environment. Support for other compiler can not be given by the developer.
The build process is written for the MinGW64 compiler. The recommended way is to use a build from TDM-GCC.
The Makefile is designed to support multiple installed gcc versions. Thats why it is necessary to set the path to the gcc version, which should be used.
If a release package should be created the 7z.exe (7-Zip) have to be in the global PATH variable. An other archiv program can be used by changing the ZIP variable. But you will probably have to change the parameters in the release targets, too.