For future visitors, who is facing this problem, this is a problem with new versions Mac OS where the CC compiler is defaulted to use C99 standard. Tk modules make files have test code that is not compatible with this standard. So, add following env variable to your bashrc or zshrc to solve this problem. There are other places where compiler flags can be passed.. google around for those.
export CFLAGS="-ansi"
export LDFLAGS="-ansi"
export CPPFLAGS="-ansi"