Don't silently swallow errors in linked-thread

syndicate/driver-support.rkt

@@ -5,6 +5,7 @@
 (provide linked-thread)
 
 (require "engine.rkt")
+(require (only-in racket/exn exn->string))
 
 (define-logger syndicate/driver-support)
 
@@ -36,5 +37,12 @@
                           peer
                           (embedded
                            (thread (lambda ()
-                                     (with-handlers ([(lambda (_e) #t) (lambda (_e) (void))]) (thunk))
+                                     (with-handlers
+                                         ([(lambda (_e) #t)
+                                           (lambda (e)
+                                             (log-syndicate/driver-support-error "~a crashed:\n~a"
+                                                                                 name
+                                                                                 (exn->string e))
+                                             (void))])
+                                       (thunk))
                                      (turn-freshen this-turn !)))))))))