[bug#32711] [PATCH] ui: Fix abort on #\nul character in build output.

[ericbavier]

From: Eric Bavier <address@hidden>

Fixes build of "lz4" package, e.g.

* guix/ui.scm (build-output-port)[handle-string]: Check for #\nul before doing
any regex matching.
---
 guix/ui.scm | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/guix/ui.scm b/guix/ui.scm
index c55ae7e2f..207aba8ad 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -1762,18 +1762,19 @@ phase announcements and replaces any other output with 
a spinner."
                      RED BLUE RED BLUE RED BLUE))))
       (lambda (str)
         (let ((processed
-               (any (match-lambda
-                      ((pattern #:transform transform)
-                       (and=> (string-match pattern str)
-                              transform))
-                      ((pattern . colors)
-                       (and=> (string-match pattern str)
-                              (lambda (m)
-                                (let ((substrings
-                                       (map (cut match:substring m <>)
-                                            (iota (- (match:count m) 1) 1))))
-                                  (string-join (map proc substrings colors) 
""))))))
-                    rules)))
+               (and (not (string-index str #\nul)) ;(ice-9 regex) cannot 
handle #\nul
+                    (any (match-lambda
+                          ((pattern #:transform transform)
+                           (and=> (string-match pattern str)
+                                  transform))
+                          ((pattern . colors)
+                           (and=> (string-match pattern str)
+                                  (lambda (m)
+                                    (let ((substrings
+                                           (map (cut match:substring m <>)
+                                                (iota (- (match:count m) 1) 
1))))
+                                      (string-join (map proc substrings 
colors) ""))))))
+                         rules))))
           (when spun?
             (display (string #\backspace) port))
           (if processed
-- 
2.18.0