Make setup.py errors about cmake not being installed more readable

setup.py

@@ -118,18 +118,17 @@ class CMakeBuild(build_ext):
     def get_cmake_version(self):
         try:
             out = subprocess.check_output(['cmake', '--version'])
-        except OSError:
-            raise RuntimeError("\n*******************************************************************\n" +
-                                  " CMake must be installed to build the following extensions: " +
-                               ", ".join(e.name for e in self.extensions) + 
-                               "\n*******************************************************************\n")
+        except:
+            sys.stderr.write("\nERROR: CMake must be installed to build dlib\n\n") 
+            sys.exit(1)
         return re.search(r'version\s*([\d.]+)', out.decode()).group(1)
 
     def run(self):
         cmake_version = self.get_cmake_version()
         if platform.system() == "Windows":
             if LooseVersion(cmake_version) < '3.1.0':
-                raise RuntimeError("CMake >= 3.1.0 is required on Windows")
+                sys.stderr.write("\nERROR: CMake >= 3.1.0 is required on Windows\n\n")
+                sys.exit(1)
 
         for ext in self.extensions:
             self.build_extension(ext)