Python3 fixes. mom-ocean#328

tools/tests/model.py

@@ -72,12 +72,15 @@ def build_shared(self, platform, compiler, build):
         except sp.CalledProcessError as e:
             ret = e.returncode
             output = e.output
-            print(output, file=sys.stderr)
         finally:
             os.chdir(saved_path)
 
+        output = output.decode('utf-8')
+        if ret:
+            print(output, file=sys.stderr)
+
         with open(os.path.join(shared_dir, 'build.out'), 'w') as f:
-            f.write(str(output))
+            f.write(output)
 
         return ret, shared_dir
 
@@ -112,11 +115,14 @@ def build_model(self, platform='raijin', compiler='gnu', build='DEBUG', memory_t
         except sp.CalledProcessError as e:
             ret = e.returncode
             output = e.output
-            print(output, file=sys.stderr)
         finally:
             os.chdir(saved_path)
 
+        output = output.decode('utf-8')
+        if ret:
+            print(output, file=sys.stderr)
+
         with open(os.path.join(model_dir, 'build.out'), 'w') as f:
-            f.write(str(output))
+            f.write(output)
 
         return ret, model_dir