diff --git a/git_differ.py b/git_differ.py
index b34f0a1..1c89303 100644
--- a/git_differ.py
+++ b/git_differ.py
@@ -2,11 +2,14 @@
 from git import Repo
 from os.path import isfile
 import os
+from bioconda_utils import recipe
 
-from .utils import get_brg_ci_homedir_path
+from utils import get_brg_ci_homedir_path
+from packagedb import PackageDBResource
 
 CI_HOMEDIR = get_brg_ci_homedir_path()
-COMMIT_FILE = CI_HOMEDIR + "latest_commit.data"
+COMMIT_FILE = CI_HOMEDIR + "/latest_commit.data"
+PACKAGE_CHANGED_DB_PATH = CI_HOMEDIR + "/packages_changed.yaml"
 
 
 def get_latest_commit():
@@ -17,31 +20,42 @@ def get_latest_commit():
         return sha
 
 
+def add_packages_to_packages_changed_DB(packages):
+    with PackageDBResource(PACKAGE_CHANGED_DB_PATH) as packageDB:
+        packageDB.add_new_packages(packages)
+
+
+def set_latest_commit_as_HEAD(recipes_path):
+    with open(COMMIT_FILE, "w") as fp:
+        fp.write(Repo(recipes_path + "/..").head.commit.hexsha)
+
+
 def retrive_packages_changed(recipes_path):
     """ Traverse bioconda-recipes and extract all packages which has changed.
 
         Assumptions: We can safely ignore Bioconductor and R packages
         """
-    print("Fetching packages Name and Source...")
-    packages = []
+    print("Fetching packages changed...")
+    packages = dict()
     num_of_packages = 0
     num_of_skipped = 0
+    num_of_errors = 0
     if isfile(COMMIT_FILE):
         latest_commit = get_latest_commit()
-        head_commit = git.Repo(recipes_path + "/..").head.commit
-        diff = hcommit.diff(latest_commit)
+        head_commit = Repo(recipes_path + "/..").head.commit
+        diff = head_commit.diff(latest_commit)
         dirs = [item.a_path.split("/")[1] for item in diff]
     else:
         _, dirs, _ = next(os.walk(recipes_path))
+    num_of_packages = len(dirs)
     for dir in dirs:
-        num_of_packages += 1
         # Skip Bioconductor or R packages
         if "bioconductor" in dir or dir.startswith("r-"):
             num_of_skipped += 1
             continue
         meta_yaml_path = "%s/%s/meta.yaml" % (recipes_path, dir)
         try:
-            if not os.path.isfile(meta_yaml_path):
+            if not isfile(meta_yaml_path):
                 continue
             current_recipe = recipe.Recipe.from_file(recipes_path, meta_yaml_path)
             name = current_recipe.name
@@ -51,11 +65,17 @@ def retrive_packages_changed(recipes_path):
                     url = url[0]
             except:
                 print("%s raised an Error" % name)
+                num_of_errors += 1
                 continue
-            packages.append(Package(name, url))
+            packages.update({name: url})
+            print(packages)
         except:
             print("%s raised an Error" % dir)
+            num_of_errors += 1
+    add_packages_to_packages_changed_DB(packages)
+    set_latest_commit_as_HEAD(recipes_path)
     print("%d out of %d packages where skipped" % (num_of_skipped, num_of_packages))
+    print("%d errors occured" % num_of_errors)
 
 
 def main():
@@ -65,8 +85,9 @@ def main():
     parser.add_argument(
         "recipes_path", help="The path to the bioconda-recipe/recipes directory"
     )
-    get_all_source_urls(args.recipes_path)
+    args = parser.parse_args()
+    retrive_packages_changed(args.recipes_path)
 
 
-if __name == "__main__":
+if __name__ == "__main__":
     main()
diff --git a/packagedb.py b/packagedb.py
index ac1b387..e16e9b0 100644
--- a/packagedb.py
+++ b/packagedb.py
@@ -1,6 +1,7 @@
 import fcntl
 from ruamel_yaml import YAML
 import hashlib
+from os.path import isfile
 
 
 class PackageDBResource:
@@ -41,9 +42,15 @@ class PackageDB:
             """
 
             def __init__(self, DB_path):
-                self._fp = open(DB_path, "r+")
-                fcntl.lockf(self._fp, fcntl.LOCK_EX)
-                self.__load_packages()
+                if isfile(DB_path):
+                    self._fp = open(DB_path, "r+")
+                    fcntl.lockf(self._fp, fcntl.LOCK_EX)
+                    self.__load_packages()
+                else:
+                    self._fp = open(DB_path, "w")
+                    fcntl.lockf(self._fp, fcntl.LOCK_EX)
+                    self._sha = ""
+                    self._packages = dict()
 
             def __load_packages(self):
                 yaml_dict = YAML().load(self._fp)
diff --git a/utils.py b/utils.py
index b5ac0d5..94f3874 100644
--- a/utils.py
+++ b/utils.py
@@ -7,5 +7,5 @@ def get_brg_ci_homedir_path():
     if isdir(CI_HOMEDIR):
         return CI_HOMEDIR
     else:
-        os.mkdir(CI_HOMEDIR)
+        mkdir(CI_HOMEDIR)
         return CI_HOMEDIR