[Emacspeak] problem running make config with emacspeak master

[prayner@xxxxxxxxxxx]

I've just installed emacs from github and cloned the current
emacspeak.
I'm getting a problem with make config which I've traced to the
construction:
 (substring
    (cl-first
     (split-string
      (shell-command-to-string
       "pacmd list-sinks | grep tts | cut -f 2 -d ':'")))
    1 -1)
    that shell-command returns an empty string for me so the substring
    seems to break.
    That breaks the defcustom for tts-notification-device
Should I patch or does this reveal a deeper problem? Setting nil as
default in the defcustom does generate a successful startup.
cheers
Peter
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