there might be some reasons :

• your $PATH is pointing to a different C compiler

• can be due to updating go or MinGW

do this:

• check go ends (CC, CXX, AR, GOARCH, GOOS) if CC is pointing ti wrong MinGW gcc that is the problem

• check MinGW64 toolchain is installed and it is on $PATH

• you can force go to use specific compiler by setting CC and CXX env

• check go and MinGW version compatibility

if you can build with "CGO_ENABLED=0 GOOS=windows GOARCH=amd64" envs it is probably MinGW related problem