prefix-gnulib-mk: give better diagnostics

* build-aux/prefix-gnulib-mk: Don't just "die".
Give better diagnostics upon failure.

diff --git a/ChangeLog b/ChangeLog
index 0b9f30f..98d74d3 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-01-27  Jim Meyering  <jim@meyering.net>
+
+       prefix-gnulib-mk: give better diagnostics
+       * build-aux/prefix-gnulib-mk: Don't just "die".
+       Give better diagnostics upon failure.
+
 2013-03-13  Paul Eggert  <eggert@cs.ucla.edu>
 
        putenv: port to Solaris 10

diff --git a/build-aux/prefix-gnulib-mk b/build-aux/prefix-gnulib-mk
index 7553f65..4d0518f 100755 (executable)
--- a/build-aux/prefix-gnulib-mk
+++ b/build-aux/prefix-gnulib-mk
@@ -189,10 +189,11 @@ sub process ($)
 {
   my ($file) = @_;
   my ($bak) = "$file.bak";
-  rename ($file, $bak) or die;
+  rename ($file, $bak) or die "$ME: rename $file $bak failed: $!\n";
   my $contents = contents ($bak);
   $contents = prefix ($contents);
-  my $out = new IO::File(">$file") or die;
+  my $out = new IO::File(">$file")
+    or die "$ME: $file: failed to open for writing: $!\n";
   print $out $contents;
 }