fedora dist-upgrade attempt

dist-upgrade.diff

diff --git a/vmupdate/agent/source/dnf/dnf_api.py b/vmupdate/agent/source/dnf/dnf_api.py
index 814e6a7..a44734e 100644
--- a/vmupdate/agent/source/dnf/dnf_api.py
+++ b/vmupdate/agent/source/dnf/dnf_api.py
@@ -19,6 +19,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 # USA.
 
+import sys
 import subprocess
 import dnf
 from dnf.yum.rpmtrans import TransactionDisplay
@@ -78,13 +79,27 @@ class DNF(DNFCLI):
 
         result = ProcessResult()
         try:
-            self.log.debug("Performing package upgrade...")
-            self.base.upgrade_all()
+            if version_upgrade:
+                self.log.debug("Performing a version upgrade...")
+                self.base.conf.releasever = version_upgrade
+
+                # refresh repos with the newly updated releasever
+                # self.base.read_all_repos()
+                # self.base.fill_sack()
+                self.base.distro_sync()
+            else:
+                self.log.debug("Performing package upgrade...")
+
+            self.base.upgrade_all() # possibly ignore
+
+            print('enabled repos', file=sys.stderr)
+            for repo in self.base.repos.iter_enabled():
+                print(f'repoid {repo.metalink}', file=sys.stderr)
 
             # fill empty `Command line` column in dnf history
             self.base.cmds = ["qubes-vm-update"]
 
-            self.base.resolve()
+            self.base.resolve(allow_erasing = bool(version_upgrade))
             trans = self.base.transaction
             if not trans:
                 self.log.info("No packages to upgrade, quitting.")