turn back on sigchanyzer: fix lint errors

.golangci.yml

@@ -32,8 +32,6 @@ linters-settings:
       # to possibly non-intuitive layout of struct fields (harder to read). Disable
       # `fieldalignment` check here until we evaluate if it is worthwhile.
       - fieldalignment
-      # https://github.com/golangci/golangci-lint/issues/1973
-      - sigchanyzer
   lll:
     line-length: 140
   misspell:

d2app/app.go

@@ -141,7 +141,9 @@ func (a *App) startDedicatedServer() error {
 		return srvErr
 	}
 
-	c := make(chan os.Signal)
+	// We must use a buffered channel or risk missing the signal
+	// if we're not ready to receive when the signal is sent.
+	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM) // This traps Control-c to safely shut down the server
 
 	go func() {