https://bugs.gentoo.org/836904

--- a/volume.el
+++ b/volume.el
@@ -448,7 +448,7 @@
 
 (when (fboundp 'define-obsolete-variable-alias)
   (define-obsolete-variable-alias 'volume-amixer-control
-    'volume-amixer-default-channel))
+    'volume-amixer-default-channel ""))
 
 (defvar volume-amixer-current-channel volume-amixer-default-channel
   "The name of the ALSA mixer channel to manipulate.")
@@ -562,7 +562,7 @@
 
 (when (fboundp 'define-obsolete-function-alias)
   (define-obsolete-function-alias 'volume-channel-name
-    'volume-channel-label))
+    'volume-channel-label ""))
 
 (defun volume-channels ()
   "Return the list of available channels."
@@ -775,7 +775,7 @@
   (volume-lower (* n 10)))
 
 (defalias 'volume-lower-more 'volume-lower-10)
-(make-obsolete 'volume-lower-more 'volume-lower-10)
+(make-obsolete 'volume-lower-more 'volume-lower-10 "")
 
 (defun volume-raise-10 (&optional n)
   "Raise the volume by 10 N percentage units."
@@ -783,7 +783,7 @@
   (volume-raise (* n 10)))
 
 (defalias 'volume-raise-more 'volume-raise-10)
-(make-obsolete 'volume-raise-more 'volume-raise-10)
+(make-obsolete 'volume-raise-more 'volume-raise-10 "")
 
 (defun volume-lower-50 (&optional n)
   "Lower the volume by 50 N percentage units."