singlejob takes a package name as parameter

and just builds this one enforced with verbose output

PBuild/Checker.pm

@@ -196,6 +196,7 @@ recheck_package:
     my ($status, $error) = check($ctx, $p, $incycle);
     #printf("%s -> %s%s", $packid, $status, $error && $status ne 'scheduled' ? " ($error)" : '');
     if ($status eq 'scheduled') {
+      next if $ctx->{'singlejob'} && $ctx->{'singlejob'} ne $packid;
       my $builder;
       for (@$builders) {
 	next if $_->{'job'};

PBuild/Options.pm

@@ -33,7 +33,7 @@ my %known_options = (
   'no-clean' => 'noclean',
   'nochecks' => 'nochecks',
   'no-checks' => 'nochecks',
-  'singlejob' => 'singlejob',
+  'singlejob' => 'singlejob:',
   'shell' => 'shell',
   'shell-after-fail' => 'shell-after-fail',
   'arch' => 'arch:',
@@ -184,6 +184,8 @@ sub parse_options {
     $opts{'singlejob'} = 1;
     $opts{'buildjobs'} = 1;
   }
+  # enforce the rebuild of the singlejob build
+  $opts{'rebuild-pkg'} = $opts{'singlejob'} if $opts{'singlejob'};
 
   return (\%opts, @back);
 }

pbuild

@@ -418,6 +418,7 @@ while (1) {
   $runs++;
   $ctx->{'buildconfig'} = $buildconfig;
   $ctx->{'lastcheck'} = \%lastcheck;
+  $ctx->{'singlejob'} = $opts->{'singlejob'} if $opts->{'singlejob'};
 
   # check status of all packages
   my $result = $ctx->pkgcheck(\@builders, @pkgs);