Print resource pools without the channel

Since the channel printer prints quite a lot of text.

knots/resource-pool.scm

@@ -20,6 +20,7 @@
 (define-module (knots resource-pool)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-9)
+  #:use-module (srfi srfi-9 gnu)
   #:use-module (ice-9 match)
   #:use-module (ice-9 exceptions)
   #:use-module (fibers)
@@ -52,6 +53,14 @@
   (name    resource-pool-name)
   (channel resource-pool-channel))
 
+(set-record-type-printer!
+ <resource-pool>
+ (lambda (resource-pool port)
+   (display
+    (simple-format #f "#<resource-pool name: \"~A\">"
+                   (resource-pool-name resource-pool))
+    port)))
+
 (define* (make-resource-pool initializer max-size
                              #:key (min-size max-size)
                              (idle-seconds #f)