Give progress its own context

The build and progress can't share the same context, the progress context
needs to live longer for the progress to be able to read all the messages
from build.

Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>

local/build.go

@@ -103,8 +103,15 @@ func (s *composeService) build(ctx context.Context, project *types.Project, opts
 			Driver: d,
 		},
 	}
+
+	// Progress needs its own context that lives longer than the
+	// build one otherwise it won't read all the messages from
+	// build and will lock
+	progressCtx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	w := progress.NewPrinter(progressCtx, os.Stdout, "auto")
+
 	// We rely on buildx "docker" builder integrated in docker engine, so don't need a DockerAPI here
-	w := progress.NewPrinter(ctx, os.Stdout, "auto")
 	_, err = build.Build(ctx, driverInfo, opts, nil, nil, w)
 	return err
 }