From: "A. Maitland Bottoms" <bottoms@debian.org>
Subject: avoid fmt trouble

Logger might not understand how to format knob type.

--- a/gnuradio-runtime/lib/controlport/thrift/rpcpmtconverters_thrift.cc
+++ b/gnuradio-runtime/lib/controlport/thrift/rpcpmtconverters_thrift.cc
@@ -111,7 +111,7 @@
         // FIXME: Don't get loggers every time we need to log something.
         gr::logger_ptr logger, debug_logger;
         gr::configure_default_loggers(logger, debug_logger, "rpcpmtconverter");
-        logger->error("ERROR Don't know how to handle Knob Type (from): {}", knob);
+        logger->error("ERROR Don't know how to handle Knob Type");
         assert(0);
     }
     return GNURadio::Knob();
