while configuring my own system (Debian) to behaves like cs50-appliance I did realize that there is a variable, CC, that I had have to change its value to "clang". And looks like, by default, Debian set up its value to "cc", that is CC=cc.
I also realized that its possible to compile some C source-code through GNU make utility using the default value of CC (cc), but a lot of source-codes only compile correctly with CC value set to "clang".
So, what is the difference in compiling with variable CC in default "cc" and set it to "clang"?