Running a rather simple program: #include <gst/gst.h> int main() { gst_init(0, NULL); g_pipeline_new("pipeline"); return 0; } with GST_DEBUG=4 causes the program to segfault when it goes to print out one of its trace messages. Can someone else please try and reproduce this? Simply, compile the above program, and run: $ GST_DEBUG=4 ./test I've tracked it down to this line of code in gstbin.c's gst_bin_init: 479 GST_DEBUG_OBJECT (bin, "using bus %" GST_PTR_FORMAT " to listen to children", 480 bus); Digging deeper, what happens is that in gst_debug_log_default, the arguments turn to rubbish, somewhere along the way. I'm using gstreamer 0.10.20, glib 2.16.3 and gcc 4.1.1 - I suspect a compiler bug, but I'd like to see if anybody else can reproduce this before I go rebuilding toolchains :) Cheers, Bernard.