diff --git a/tests/Makefile b/tests/Makefile
index febbb8393..1ecc96aa5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -51,4 +51,6 @@ default: $(AOBJS) $(COBJS) $(MAINOBJ)
 
 clean:
 	find ../ -type f -name '*.o' -exec rm -f {} +
+	find ../ -type f -name '*.gcda' -exec rm -f {} +
+	find ../ -type f -name '*.gcno' -exec rm -f {} +
 	rm -f $(BIN) 
diff --git a/tests/build.py b/tests/build.py
index 0e3f4ed77..435cc0569 100755
--- a/tests/build.py
+++ b/tests/build.py
@@ -23,7 +23,7 @@ def build(defines):
 
   print("")
   print("Build")
-  print("-----------------------")
+  print("-----------------------", flush=True)
 #  print(cmd)
   ret = os.system(cmd)
   if(ret != 0): 
@@ -32,10 +32,10 @@ def build(defines):
 
   print("")
   print("Run")
-  print("-----------------------")
+  print("-----------------------", flush=True)
   ret = os.system("./test.bin")
   if(ret != 0): 
-    print("RUN ERROR! (error code  " + str(ret) + ")")
+    print("RUN ERROR! (error code  " + str(ret) + ")", flush=True)
     exit(1)
 
 
@@ -47,7 +47,7 @@ def build_test(defines, test_name):
   print("")
   print("~~~~~~~~~~~~~~~~~~~~~~~~")
   print(re.search("/[a-z_]*$", test_name).group(0)[1:])
-  print("~~~~~~~~~~~~~~~~~~~~~~~~")
+  print("~~~~~~~~~~~~~~~~~~~~~~~~", flush=True)
   
   d_all = base_defines[:-1] + " ";
   
@@ -60,15 +60,15 @@ def build_test(defines, test_name):
   test_file_runner_name = test_file_runner_name.replace("/test_cases/", "/test_runners/")
   csrcs = " EXTRA_CSRCS=\"unity/unity.c unity/unity_support.c src/test_fonts/font_1.c src/test_fonts/font_2.c src/test_fonts/font_3.c \" "
   # -s makes it silence
-  cmd = "make -s -j BIN=test.bin MAINSRC=" + test_file_name + " TEST_SRC=" + test_file_runner_name + csrcs + "  LVGL_DIR_NAME=" + lvgldirname + " DEFINES=" + d_all + " OPTIMIZATION=" + optimization
+  cmd = "make -s -j BIN=test.bin MAINSRC=" + test_file_name + " TEST_SRC=" + test_file_runner_name + csrcs + "  LVGL_DIR_NAME=" + lvgldirname + " DEFINES=" + d_all + " OPTIMIZATION=" + optimization 
 
   print("")
   print("Build")
-  print("-----------------------")
+  print("-----------------------", flush=True)
 #  print(cmd)
   ret = os.system(cmd)
   if(ret != 0): 
-    print("BUILD ERROR! (error code  " + str(ret) + ")")
+    print("BUILD ERROR! (error code  " + str(ret) + ")", flush=True)
     exit(1)
   
   print("")
@@ -76,12 +76,12 @@ def build_test(defines, test_name):
   print("-----------------------")
   ret = os.system("./test.bin")
   if(ret != 0): 
-    print("RUN ERROR! (error code  " + str(ret) + ")")
+    print("RUN ERROR! (error code  " + str(ret) + ")", flush=True)
     exit(1)
 
 def clean():
   print("")
   print("Clean")
-  print("-----------------------")
+  print("-----------------------", flush=True)
   os.system("make clean LVGL_DIR_NAME=" + lvgldirname)
   os.system("rm -f ./test.bin")
diff --git a/tests/main.py b/tests/main.py
index f9a286897..ab8c47d27 100755
--- a/tests/main.py
+++ b/tests/main.py
@@ -12,7 +12,7 @@ def build_conf(title, defs):
   print("============================================")
   print(title)
   print("============================================")
-  print("")
+  print("", flush=True)
 
   build.clean()
   build.build(defs)
@@ -43,9 +43,9 @@ for f in files:
 if test_report:
   print("")
   print("Generating report")
-  print("-----------------------")
+  print("-----------------------", flush=True)
   os.system("rm -r report")
   os.system("mkdir report")
   os.system("gcovr -r ../ --html-details -o report/index.html  --exclude-directories '\.\./examples' --exclude-directories 'src/.*' --exclude-directories 'unity' --exclude 'lv_test_.*\.c'") 
-  print("Done: See report/index.html")
+  print("Done: See report/index.html", flush=True)
 
diff --git a/tests/test.py b/tests/test.py
index f8e6d16a4..52ca66674 100644
--- a/tests/test.py
+++ b/tests/test.py
@@ -2,8 +2,9 @@ import os
 import glob
 
 def prepare():
-  os.system("rm src/test_runners/test_*_Runner.c")
   os.system("rm src/*.o")
+  os.system("rm -rdf src/test_runners")
+  os.system("mkdir src/test_runners")
   files = glob.glob("./src/test_cases/test_*.c")
   
   for index, item in enumerate(files):
@@ -12,11 +13,10 @@ def prepare():
         break
         
   files.insert(0, "./src/test_cases/test_config.c")
-  print(files)
-  
   
   for f in files:
     r = f[:-2] + "_Runner.c"
     r = r.replace("/test_cases/", "/test_runners/")
-    os.system("ruby unity/generate_test_runner.rb " + f + " " + r + " config.yml") 
+    cmd = "ruby unity/generate_test_runner.rb " + f + " " + r + " config.yml"
+    os.system(cmd) 
   return files