--- a/CHANGELOG	Fri Apr 06 17:54:58 2018 +0200
+++ b/CHANGELOG	Thu Mar 29 13:01:05 2018 -0700
@@ -6,6 +6,7 @@
 
   * drop support for Mercurial 4.1
   * `--obsolete` and `--old-obsolete` flags for `hg graft` are dropped
+  * `hg evolve` now return 0 if there is nothing to evolve
 
   * fixed some memory leak issue
 

--- a/hgext3rd/evolve/evolvecmd.py	Fri Apr 06 17:54:58 2018 +0200
+++ b/hgext3rd/evolve/evolvecmd.py	Thu Mar 29 13:01:05 2018 -0700
@@ -749,6 +749,7 @@
     unselectedcategories = [c for c in troublecategories if c != targetcat]
     msg = None
     hint = None
+    retoverride = None
 
     troubled = {
         "orphan": repo.revs("orphan()"),
@@ -835,14 +836,20 @@
                     hint = hintmap['any+' + ('+'.join(othertroubles))]
                 else:
                     msg = _("no troubled changesets")
+                    # Exit with a 0 (success) status in this case.
+                    retoverride = 0
 
     assert msg is not None
     ui.write_err("%s\n" % msg)
     if hint:
         ui.write_err("(%s)\n" % hint)
-        return 2
+        ret = 2
     else:
-        return 1
+        ret = 1
+
+    if retoverride is not None:
+        return retoverride
+    return ret
 
 def _preparelistctxs(items, condition):
     return [item.hex() for item in items if condition(item)]

--- a/tests/test-stabilize-order.t	Fri Apr 06 17:54:58 2018 +0200
+++ b/tests/test-stabilize-order.t	Thu Mar 29 13:01:05 2018 -0700
@@ -129,7 +129,6 @@
   
   $ hg evolve -v
   no troubled changesets
-  [1]
 
 Test behavior with --any