Make examples commands return a failure

Currently the following commands in examples.py,
do_import()
do_deploy()
do_versionning()
do_clone()

all return a success status (ie 0) irrespective of any errors
originating from their sub-functions.

This PR fixes this. Now these commands will return one of:
0 - success
1 - general failure
x - failure returned by a subprocess.call function

tools/test/examples/examples.py

@@ -97,20 +97,17 @@ def do_export(args, config, examples):
 
 def do_import(_, config, examples):
     """Do the import step of this process"""
-    lib.source_repos(config, examples)
-    return 0
+    return lib.source_repos(config, examples)
 
 
 def do_clone(_, config, examples):
     """Do the clone step of this process"""
-    lib.clone_repos(config, examples)
-    return 0
+    return lib.clone_repos(config, examples)
 
 
 def do_deploy(_, config, examples):
     """Do the deploy step of this process"""
-    lib.deploy_repos(config, examples)
-    return 0
+    return lib.deploy_repos(config, examples)
 
 
 def do_compile(args, config, examples):
@@ -125,8 +122,7 @@ def do_compile(args, config, examples):
     
 def do_versionning(args, config, examples):
     """ Test update the mbed-os to the version specified by the tag """
-    lib.update_mbedos_version(config, args.tag, examples)
-    return 0
+    return lib.update_mbedos_version(config, args.tag, examples)
 
 
 if __name__ == "__main__":

tools/test/examples/examples_lib.py

@@ -169,7 +169,11 @@ def source_repos(config, examples):
                     print("'%s' example directory already exists. Deleting..." % name)
                     rmtree(name)
 
-                subprocess.call(["mbed-cli", "import", repo_info['repo']])
+                result = subprocess.call(["mbed-cli", "import", repo_info['repo']])
+                if result:
+                    return result
+    
+    return 0                
 
 def clone_repos(config, examples , retry = 3):
     """ Clones each of the repos associated with the specific examples name from the
@@ -192,6 +196,8 @@ def clone_repos(config, examples , retry = 3):
                         break
                 else:
                     print("ERROR : unable to clone the repo {}".format(name))
+                    return 1
+    return 0
 
 def deploy_repos(config, examples):
     """ If the example directory exists as provided by the json config file,
@@ -207,11 +213,15 @@ def deploy_repos(config, examples):
             if name in examples:
                 if os.path.exists(name):
                     os.chdir(name)
-                    subprocess.call(["mbed-cli", "deploy"])
+                    result = subprocess.call(["mbed-cli", "deploy"])
                     os.chdir("..")
+                    if result:
+                        print("mbed-cli deploy command failed for '%s'" % name)
+                        return result                
                 else:
                     print("'%s' example directory doesn't exist. Skipping..." % name)
-
+                    return 1
+    return  0
 
 def get_num_failures(results, export=False):
     """ Returns the number of failed compilations from the results summary
@@ -405,5 +415,10 @@ def update_mbedos_version(config, tag, examples):
             update_dir =  basename(repo_info['repo']) + "/mbed-os"
             print("\nChanging dir to %s\n" % update_dir)
             os.chdir(update_dir)
-            subprocess.call(["mbed-cli", "update", tag, "--clean"])
+            result = subprocess.call(["mbed-cli", "update", tag, "--clean"])
             os.chdir("../..")
+            if result:
+                return result:
+    
+    return 0
+