guile test stderr

shell output

;;; note: source file /home/jmickey/tmp/./test.scm
;;;       newer than compiled /home/jmickey/.cache/guile/ccache/2.0-LE-8-2.0/home/jmickey/tmp/test.scm.go
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/jmickey/tmp/./test.scm
;;; compiled /home/jmickey/.cache/guile/ccache/2.0-LE-8-2.0/home/jmickey/tmp/test.scm.go
what was stored in stdout:

<eond of os>
what was stored in stderr:

<eond of es>
what was stored in stdout:
help me i'm stdout

<eond of os>
what was stored in stderr:

<eond of es>

test.scm

(use-modules (ice-9 popen))

(define (port-copy dst src)
  (let ((c (read-char src)))
    (if (eof-object? c)
	dst
	(begin (write-char c dst)
	       (port-copy dst src)))))

(define (print-outs one two)
  (format #t "what was stored in stdout:~%~a~%<eond of os>~%" (get-output-string os))
  (format #t "what was stored in stderr:~%~a~%<eond of es>~%" (get-output-string es)))

(let ((os (open-output-string))
      (es (open-output-string)))
  (parameterize ((current-error-port es))
    (let ((rp (open-pipe* OPEN_BOTH; "dd" "if=/dev/zero" "of=/dev/zero" "bs=1" "count=20"
			  "logger" "-s" "help me i'm stderr")))
      (port-copy os rp)
      (status:exit-val (close-pipe rp))))
  (print-outs os es))

(let ((os (open-output-string))
      (es (open-output-string)))
  (parameterize ((current-error-port es))
    (let ((rp (open-pipe* OPEN_BOTH; "dd" "if=/dev/zero" "of=/dev/zero" "bs=1" "count=20"
			  "echo" "help me i'm stdout")))
      (port-copy os rp)
      (status:exit-val (close-pipe rp))))
  (print-outs os es))

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24680