diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -413,15 +413,6 @@
         if not destmap:
             return _nothingtorebase()
 
-        rebaseset = destmap.keys()
-        if not self.keepf:
-            try:
-                rewriteutil.precheck(self.repo, rebaseset, action=b'rebase')
-            except error.Abort as e:
-                if e.hint is None:
-                    e.hint = _(b'use --keep to keep original changesets')
-                raise e
-
         result = buildstate(self.repo, destmap, self.collapsef)
 
         if not result:
@@ -450,6 +441,15 @@
         # Calculate self.obsolete_* sets
         self._handleskippingobsolete()
 
+        rebaseset = destmap.keys()
+        if not self.keepf:
+            try:
+                rewriteutil.precheck(self.repo, rebaseset, action=b'rebase')
+            except error.Abort as e:
+                if e.hint is None:
+                    e.hint = _(b'use --keep to keep original changesets')
+                raise e
+
         self.prepared = True
 
     def _assignworkingcopy(self):
diff --git a/tests/test-rebase-scenario-global.t b/tests/test-rebase-scenario-global.t
--- a/tests/test-rebase-scenario-global.t
+++ b/tests/test-rebase-scenario-global.t
@@ -325,9 +325,8 @@
 
   $ hg pull --config phases.publish=True -q -r 6 . # update phase of 6
   $ hg rebase -d 0 -b 6
-  abort: cannot rebase public changesets
-  (see 'hg help phases' for details)
-  [10]
+  nothing to rebase
+  [1]
   $ hg rebase -d 5 -b 6
   abort: cannot rebase public changesets
   (see 'hg help phases' for details)