diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -154,6 +154,8 @@
         ui.warn(_("abort: %s\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
+        if inst.errlist:
+            ui.warn("  " + "\n  ".join(inst.errlist) + "\n")
     except ImportError, inst:
         ui.warn(_("abort: %s!\n") % inst)
         m = str(inst).split()[-1]
diff --git a/mercurial/error.py b/mercurial/error.py
--- a/mercurial/error.py
+++ b/mercurial/error.py
@@ -35,6 +35,7 @@
     def __init__(self, *args, **kw):
         Exception.__init__(self, *args)
         self.hint = kw.get('hint')
+        self.errlist = kw.get('errlist')

 class ConfigError(Abort):
     'Exception raised when parsing config files'
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -90,11 +90,16 @@
     folded = {}
     for fn in mctx:
         folded[foldf(fn)] = fn
+
+    errlist = list()
     for fn in wctx.unknown():
         f = foldf(fn)
         if f in folded and mctx[folded[f]].cmp(wctx[f]):
-            raise util.Abort(_("untracked file in working directory differs"
-                               " from file in requested revision: '%s'") % fn)
+            errlist.append(fn)
+    if errlist:
+        raise util.Abort("untracked file(s) in working directory differ"
+                         " from file(s) in requested revision: ",
+                         errlist=errlist)

 def _checkcollision(mctx, wctx):
     "check for case folding collisions in the destination context"