Editing setup.py to locate nvcc and detect cuda major version more strictly

setup.py

@@ -71,11 +71,18 @@ def findcuda():
         raise RuntimeError("Error: Could not find cuda on this system."+
                            " Please set your CUDA_HOME enviornment variable to the CUDA base directory.")
     
-    NVCC = find(CUDA_HOME, re.compile('nvcc').search)
-    CUDA_LIB = find(CUDA_HOME, re.compile('libcudart.so.*.*.*').search)
+    NVCC = find(CUDA_HOME+os.sep+"bin", 
+                re.compile('nvcc$').search)
+    print("Found NVCC = ", NVCC)
+
+    # Parse output of nvcc to get cuda major version
+    nvcc_output = subprocess.check_output([NVCC, '--version']).decode("utf-8")
+    CUDA_LIB = re.compile(', V[0-9]+\.[0-9]+\.[0-9]+').search(nvcc_output).group(0).split('V')[1]
+    print("Found CUDA_LIB = ", CUDA_LIB)
+
     if CUDA_LIB:
         try:
-            CUDA_VERSION = int(CUDA_LIB.split('.')[2])
+            CUDA_VERSION = int(CUDA_LIB.split('.')[0])
         except (ValueError, TypeError):
             CUDA_VERSION = 9
     else: