Maybe you're hitting the logger_ptr bug? See <
https://github.com/gnuradio/gnuradio/issues/1383 > for more info. It happens when GR is built with logging enabled but not log4cpp, and then the OOT is built either with logging enable and log4cpp or logging not enabled. The "free" on gr::block ends up corrupting the stack because the logger_ptr is of the wrong size in the OOT block (when compared with that compiled into gnuradio_runtime). Not sure if this is the issue here, but this is happening during gr::flowgraph::clear (which just clears the blocks and then edges), so, maybe? An easy test is to rebuild the OOT with logging same-same as GR's. - MLD