() ng0 <ng0@libertad.pw>
() Tue, 27 Dec 2016 12:42:13 +0000

   (system* "notmuch" "search" "--output=files" "tag:deleted" 
   "|" "xargs" "-L" "1" "rm")

Here's what i would do (untested):

(use-modules (ice-9 popen) (ice-9 rdelim))
(let* ((port (open-input-pipe "notmuch ..."))
       ;; no loop necessary, we only want one
       (filename (read-line port)))
  (close-port port)
  (delete-file filename))

Since this response is very late, i wonder if you have already
found a solution.  If so, would you mind posting it?

-- 
Thien-Thi Nguyen -----------------------------------------------
 (defun responsep (query)
   (pcase (context query)
     (`(technical ,ml) (correctp ml))
     ...))                              748E A0E8 1CB8 A748 9BFA
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