write debug output to ~/.config/fcscs/log

Reverts 30ff4d3e ("run_in_background: fix execution when debug mode is
enabled") which is no longer necessary as debug output in background
processes works fine now.

diff --git a/bin/fcscs b/bin/fcscs
index 8cffebd6ff049e78dbcc54f0ae2634e4747e89e0..7543a9df7807c10ed3a89dda3a89f714f8b9e0f9 100755 (executable)
--- a/bin/fcscs
+++ b/bin/fcscs
@@ -344,7 +344,18 @@ package Screen {
 sub debug {
     my ($config, $module, @args) = @_;
 
-    say STDERR "$module: @args" if $config->{setting}{debug};
+    return if not $config->{setting}{debug};
+
+    state $fh; # only open the file once per run
+    if (not defined $fh) {
+        # Ignore errors if the directory doesn't exist.
+        if (not open $fh, '>', "$ENV{HOME}/.config/fcscs/log") {
+            $fh = undef; # a failed open still writes a value to $fh
+            return;
+        }
+    }
+
+    say $fh "$module: @args";
     return;
 }
 
@@ -461,9 +472,6 @@ sub run_in_background {
         my $pid = fork;
         defined $pid or die $!;
         if ($pid == 0) { # child
-            # Disable debug mode as writing will fail with closed STDERR.
-            $config->{setting}{debug} = 0;
-
             $sub->();
         }
         exit;
@@ -904,7 +912,7 @@ Defaults in parentheses.
 
 =over
 
-=item B<debug>          enable debug mode (redirect stderr when enabling) (C<0>)
+=item B<debug>          enable debug mode, writes to I<~/.config/fcscs/log> (C<0>)
 
 =item B<initial_mode>   start in this mode, must be a valid mode mapping (C<\&mapping_mode_url>)