diff --git a/scripts/fetch_nightly_versions.py b/scripts/fetch_nightly_versions.py
index cff95c14..5efb9b81 100755
--- a/scripts/fetch_nightly_versions.py
+++ b/scripts/fetch_nightly_versions.py
@@ -48,64 +48,14 @@ def get_latest_commit(
 
     return commit
 
-
-def get_default_branch(
-    name,
-    repoinfo,
-    # for now supporting only gitlab.cern.ch
-    gitlab=False,
-    date=None,
-):
-    """Helper function for adding a package versioned at the latest commit to a spack environment.
-    The authentication is optional, but note that the api might be rate-limited for unauthenticated access.
-
-    :param name: spack name of the package, p.ex: "edm4hep"
-    :param repoinfo: description of the owner and repository names, p.ex: "key4hep/edm4hep"
-    """
-
-    if not gitlab:
-        giturl = "https://api.github.com/repos/%s"
-    else:
-        giturl = "https://gitlab.cern.ch/api/v4/projects/%s"
-
-    if gitlab:
-        repoinfo = repoinfo.replace("/", "%2F")
-
-    # Apparently this is also fine for gitlab
-    headers = {"Accept": "application/vnd.github+json"}
-
-    # gitlab doesn't seem to need a token, maybe there is some rate limiting without one
-    token = os.environ.get("GITHUB_TOKEN" if not gitlab else "CERN_GITLAB_TOKEN", None)
-    if token:
-        headers["Authorization" if not gitlab else "PRIVATE-TOKEN"] = f"token {token}"
-
-    # not tested for gitlab
-    search_params = {}
-    if date:
-        search_params = {
-            "until": f"{date}",
-        }
-
-    response = requests.get(giturl % repoinfo, params=search_params, headers=headers)
-
-    default_branch = response.json()[
-        "default_branch" if not gitlab else "default_branch"
-    ]
-
-    return default_branch
-
-
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(
         description="Add latest commits to a spack environment"
     )
     parser.add_argument(
-        "--path",
-        help="path to a yaml file with spack packages",
-    )
-    parser.add_argument(
-        "--extra-path",
-        help="path to a yaml file with spack packages",
+        "path",
+        help="path to the current environment",
+        default="/key4hep-spack",
     )
     parser.add_argument(
         "date",
@@ -116,19 +66,12 @@ def get_default_branch(
     date = args.date
 
     try:
-        with open(args.path, "r") as recipe:
+        with open(os.path.join(args.path, "packages.yaml"), "r") as recipe:
             text = yaml.safe_load(recipe)
     except FileNotFoundError:
         print("Please run this script from the key4hep-spack repository.")
         raise
 
-    try:
-        with open(args.extra_path, "r") as recipe:
-            text_extra = yaml.safe_load(recipe)
-    except FileNotFoundError:
-        print("Please run this script from the key4hep-spack repository.")
-        raise
-
     for package, location in [
         ("aidatt", "aidasoft/aidatt"),
         ("ced", "ilcsoft/ced"),
@@ -188,24 +131,15 @@ def get_default_branch(
         gitlab = False
         if package in ["opendatadetector"]:
             gitlab = True
-        commit = get_default_branch(package, location, gitlab=gitlab, date=date)
-        line = f"@{commit} "
-        # if package not in ["cepcsw"]:
-        #     line += "=develop"
-        original = " "
-        if package in text["packages"] and "require" in text["packages"][package]:
-            original = text["packages"][package]["require"]
-            text["packages"][package]["require"] = line + original
-        elif (
-            package in text_extra["packages"]
-            and "require" in text_extra["packages"][package]
-        ):
-            original = text_extra["packages"][package]["require"]
-            text_extra["packages"][package]["require"] = line + original
+        commit = get_latest_commit(package, location, date=date, gitlab=gitlab)
+        line = f"@{commit}"
+        if package not in ["cepcsw"]:
+            line += "=develop"
+        if not text["packages"][package]:
+            print(f"Adding {package}@{commit} to the key4hep-stack package.py")
         else:
-            text_extra["packages"][package]["require"] = line
+            print(f"Updating {package}@{commit} in the key4hep-stack package.py")
+        text["packages"][package]["require"] = line
 
-    with open(args.path, "w") as recipe:
+    with open(os.path.join(args.path, "packages.yaml"), "w") as recipe:
         yaml.dump(text, recipe)
-    with open(args.extra_path, "w") as recipe:
-        yaml.dump(text_extra, recipe)