diff --git a/mercurial/config.py b/mercurial/config.py
--- a/mercurial/config.py
+++ b/mercurial/config.py
@@ -200,7 +200,10 @@
                 self._unset.append((section, name))
                 continue
 
-            raise error.ParseError(l.rstrip(), (b"%s:%d" % (src, line)))
+            message = l.rstrip()
+            if l.startswith(b' '):
+                message = b"unexpected leading whitespace: %s" % message
+            raise error.ParseError(message, (b"%s:%d" % (src, line)))
 
     def read(self, path, fp=None, sections=None, remap=None):
         if not fp:
diff --git a/mercurial/dispatch.py b/mercurial/dispatch.py
--- a/mercurial/dispatch.py
+++ b/mercurial/dispatch.py
@@ -248,8 +248,6 @@
             _(b"hg: parse error at %s: %s\n")
             % (pycompat.bytestr(inst.location), inst.message)
         )
-        if inst.message.startswith(b' '):
-            write(_(b"unexpected leading whitespace\n"))
     else:
         write(_(b"hg: parse error: %s\n") % inst.message)
         _reportsimilar(write, similar)
diff --git a/tests/test-config.t b/tests/test-config.t
--- a/tests/test-config.t
+++ b/tests/test-config.t
@@ -25,8 +25,7 @@
   >  key=value
   > EOF
   $ hg showconfig
-  hg: parse error at $TESTTMP/.hg/hgrc:1:  key=value
-  unexpected leading whitespace
+  hg: parse error at $TESTTMP/.hg/hgrc:1: unexpected leading whitespace:  key=value
   [255]
 
   $ cat > .hg/hgrc << EOF
@@ -34,8 +33,7 @@
   > key=value
   > EOF
   $ hg showconfig
-  hg: parse error at $TESTTMP/.hg/hgrc:1:  [section]
-  unexpected leading whitespace
+  hg: parse error at $TESTTMP/.hg/hgrc:1: unexpected leading whitespace:  [section]
   [255]
 
 Reset hgrc
diff --git a/tests/test-hgrc.t b/tests/test-hgrc.t
--- a/tests/test-hgrc.t
+++ b/tests/test-hgrc.t
@@ -68,8 +68,7 @@
   $ echo '[foo]' > $HGRC
   $ echo '  x = y' >> $HGRC
   $ hg version
-  hg: parse error at $TESTTMP/hgrc:2:   x = y
-  unexpected leading whitespace
+  hg: parse error at $TESTTMP/hgrc:2: unexpected leading whitespace:   x = y
   [255]
 
   $ "$PYTHON" -c "from __future__ import print_function; print('[foo]\nbar = a\n b\n c \n  de\n fg \nbaz = bif cb \n')" \