diff.diff

diff --git a/src/core/Proc.pm b/src/core/Proc.pm
index 955e26a..3e14816 100644
--- a/src/core/Proc.pm
+++ b/src/core/Proc.pm
@@ -21,7 +21,9 @@ my class Proc {
                     Str :$enc, Str:D :$nl = "\n", :$signal --> Nil) {
         @!command = |$command if $command;
         if nqp::istype($in, IO::Handle) && $in.DEFINITE {
-            @!pre-spawn.push({ $!proc.bind-stdin($in) });
+            @!pre-spawn.push({
+                $!proc.bind-stdin($in);
+            });
         }
         elsif $in === True {
             $!in = IO::Pipe.new(:proc(self), :$chomp, :$enc, :$bin, nl-out => $nl,
@@ -51,14 +53,21 @@ my class Proc {
             if $out === True {
                 my $chan = Channel.new;
                 $!out = IO::Pipe.new(:proc(self), :$chomp, :$enc, :$bin, nl-in => $nl,
-                    :on-read({ (try $chan.receive) // buf8.new }),
+                    :on-read({
+                        my $rec = try $chan.receive;
+                        $! and say "Error!!! $!.^name()";
+                        $rec // buf8.new;
+                    }),
                     :on-close({ self!await-if-last-handle }),
                     :bin-supply({ $chan.Supply }));
                 $!active-handles++;
                 @!pre-spawn.push({
-                    $!proc.stdout(:bin).tap: { $chan.send($_) },
-                        done => { $chan.close },
-                        quit => { $chan.fail($_) }
+                    $!proc.stdout(:bin).tap: {
+                        dd ["stdout tap {@!command[]}", 'sending'];
+                        $chan.send($_) },
+                        done => { dd ["stdout tap {@!command[]}", 'donning']; $chan.close
+                      },
+                        quit => { dd ["stdout tap {@!command[]}", 'quitting']; $chan.fail($_) }
                 });
             }
             elsif nqp::istype($out, IO::Handle) && $out.DEFINITE {
diff --git a/src/core/Proc/Async.pm b/src/core/Proc/Async.pm
index 7d24050..c1f22b8 100644
--- a/src/core/Proc/Async.pm
+++ b/src/core/Proc/Async.pm
@@ -162,10 +162,10 @@ my class Proc::Async {
         die "Can only bind an output IO::Pipe to stdin of a process"
             unless $sup.DEFINITE;
         $!w = True;
-        $!ready_promise.then({
-            $sup().tap: { self.write($_) },
-                done => { self.close-stdin },
-                quit => { self.close-stdin };
+        $!ready_promise := $!ready_promise.then({
+            $sup().tap: { dd ['bind-stdin', 'writing']; self.write($_) },
+                done => { dd ['bind-stdin', 'donning']; self.close-stdin },
+                quit => { dd ['bind-stdin', 'quitting']; self.close-stdin };
         });
     }
 
diff --git a/src/core/Rakudo/Internals.pm b/src/core/Rakudo/Internals.pm
index 38d26a9..2e31b10 100644
--- a/src/core/Rakudo/Internals.pm
+++ b/src/core/Rakudo/Internals.pm
@@ -510,6 +510,7 @@ my class Rakudo::Internals {
         }
 
         method process(Mu \seq, Mu \data, Mu \err) {
+            dd ['Supply Sequencer processing', [data, err] ];
             $!lock.protect: {
                 if err {
                     &!on-error(err);