s/NOCUDA/NO_CUDA/

Signed-off-by: Edward Z. Yang <ezyang@fb.com>

Author: ezyang

CONTRIBUTING.md

@@ -72,10 +72,10 @@ You do not need to repeatedly install after modifying python files.
 
 #### C++ Development tips
 
-When you are developing on the C++ side of things, the environment variables `DEBUG` and `NOCUDA` are helpful.
+When you are developing on the C++ side of things, the environment variables `DEBUG` and `NO_CUDA` are helpful.
 
 - `DEBUG=1` will enable debug builds (-g -O0)
-- `NOCUDA=1` will disable compiling CUDA (in case you are developing on something not CUDA related), to save compile time.
+- `NO_CUDA=1` will disable compiling CUDA (in case you are developing on something not CUDA related), to save compile time.
 
 For example:
 ```