deptool: Moved to one global fetch

Anecdotally, it seems like one git fetch --all --tags
will be faster than several specific fetches.

It also "avoids" the problem of what the remote is called,
previously origin was assumed, however for me the "correct" one to
use is upstream, or --all.

Signed-off-by: Ole Herman Schumacher Elgesem <ole.elgesem@northern.tech>

Author: olehermanse

src/cfengine_cli/deptool.py

@@ -126,6 +126,7 @@ def __init__(
 
         if not os.path.exists(repo_path):
             self.run_command("clone", "--no-checkout", repo_url, repo_path)
+        self.run_command("fetch", "--all", "--tags")
         if checkout_ref is not None:
             self.checkout(checkout_ref)
 
@@ -166,24 +167,17 @@ def run_command(self, *command, **kwargs):
 
         return result
 
-    def checkout(self, ref, remote="origin", new=False):
+    def checkout(self, ref, new=False):
         """Checkout given ref (branch or tag), optionally creating the ref as a branch.
         Note that it's an error to create-and-checkout branch which already exists.
         """
         if new:
             # create new branch
             self.run_command("checkout", "-b", ref)
         else:
-            # first, ensure that we're aware of target ref
-            # TODO: Move this to one global fetch, it will be
-            #       generally faster and not break when remote
-            #       is something else (i.e. upstream, not origin).
-            #       git fetch --all --tags
-            self.run_command("fetch", remote, ref)
-            # switch to the ref
             self.run_command("checkout", ref)
             # ensure we're on the tip of ref
-            self.run_command("reset", "--hard", "FETCH_HEAD")
+            self.run_command("reset", "--hard", "HEAD")
         self.run_command("submodule", "update", "--init")
 
     def get_file(self, relpath):
@@ -322,6 +316,7 @@ def deps_versions(self, ref):
 
         deps_versions = {}
         deps_list = self.deps_list(ref)
+        assert len(deps_list) > 1
         for dep in deps_list:
             if dep == "$EMBEDDED_DB":
                 continue