#0  0x00007f8dc76dd07f in pushbuf_kref (push=push@entry=0x564379e96ea0, bo=0x0, flags=0) at ../../nouveau/pushbuf.c:165
        dev = 0x564379e96f60
        krec = 0x564379e974b0
        kref = <optimized out>
        domains = 0
        domains_wr = <optimized out>
        domains_rd = <optimized out>
#1  0x00007f8dc76dd709 in pushbuf_validate (push=0x564379e96ea0, retry=<optimized out>) at ../../nouveau/pushbuf.c:506
        krec = <optimized out>
        kref = <optimized out>
        bctx = 0x564379f13620
        bref = 0x564379f13648
        relocs = <optimized out>
        sref = 7
        srel = 0
        ret = 0
#2  0x00007f8dc76dd98a in nouveau_pushbuf_validate (push=<optimized out>) at ../../nouveau/pushbuf.c:753
No locals.
#3  0x00007f8dc8000a4f in nv50_state_validate (nv50=nv50@entry=0x564379ee91d0, mask=mask@entry=4096, validate_list=validate_list@entry=0x7f8dc866d5a0 <validate_list_3d>, size=size@entry=26, dirty=dirty@entry=0x564379ee95c8, bufctx=0x564379ee72a0) at ../../../../../src/gallium/drivers/nouveau/nv50/nv50_state_validate.c:582
        state_mask = <optimized out>
        ret = <optimized out>
        i = <optimized out>
#4  0x00007f8dc8000c07 in nv50_state_validate_3d (nv50=nv50@entry=0x564379ee91d0, mask=mask@entry=4096) at ../../../../../src/gallium/drivers/nouveau/nv50/nv50_state_validate.c:592
        ret = <optimized out>
#5  0x00007f8dc8002e61 in nv50_clear (pipe=0x564379ee91d0, buffers=4, color=0x7f8dd01cdac4, depth=1, stencil=0) at ../../../../../src/gallium/drivers/nouveau/nv50/nv50_surface.c:538
        push = 0x564379e96ea0
        fb = 0x564379eea3d8
        i = <optimized out>
        j = <optimized out>
        k = <optimized out>
        mode = 0
#6  0x00007f8dc7cc1341 in st_Clear (ctx=0x7f8dd01cc010, mask=2) at ../../../src/mesa/state_tracker/st_cb_clear.c:481
        depthRb = <optimized out>
        stencilRb = <optimized out>
        quad_buffers = <optimized out>
        clear_buffers = <optimized out>
        i = <optimized out>
#7  0x00007f8dcfec9e91 in mir::renderer::gl::Renderer::render(std::vector<std::shared_ptr<mir::graphics::Renderable>, std::allocator<std::shared_ptr<mir::graphics::Renderable> > > const&) const (this=0x7f8dbc0008c0, renderables=...) at ./src/renderers/gl/renderer.cpp:245
No locals.
#8  0x00007f8dcfe848e5 in composite (this=this@entry=0x7f8dbc003620, scene_elements=scene_elements@entry=<unknown type in /tmp/apport_sandbox_gkegru/usr/lib/debug/.build-id/8d/754cd384b483cf175c93716f25d6d3188dd846.debug, CU 0x328de0, DIE 0x34faaa>) at ./src/server/compositor/default_display_buffer_compositor.cpp:83
        view_area = @0x7f8dc1d1e940: {top_left = {x = {value = 0}, y = {value = 0}}, size = {width = {value = 1920}, height = {value = 1080}}}
        occlusions = <optimized out>
        renderable_list = {<No data fields>}
#9  0x00007f8dcfe837a8 in operator() (this=0x564379f8a380) at ./src/server/compositor/multi_threaded_compositor.cpp:141
        __for_range = @0x7f8dc1d1eb00: {<No data fields>}
        delay = <optimized out>
        pending = <optimized out>
        lock = {_M_device = 0x564379f8a3b8, _M_owns = false}
        compositors = {<No data fields>}
        disp_listener = {<No data fields>}
        display_registration = {deleter = {__this = 0x564379f8a380, __disp_listener = @0x7f8dc1d1eab0}, owner = true}
        compositor_registration = {deleter = {__this = 0x564379f8a380, __compositors = @0x7f8dc1d1eb00}, owner = true}
#10 0x00007f8dcfecd059 in operator() () at /usr/include/c++/6/functional:2127
No locals.
#11 execute (this=0x7f8dc1d1ec70) at ./src/server/thread/basic_thread_pool.cpp:40
No locals.
#12 operator() (this=0x564379f8a4b0) at ./src/server/thread/basic_thread_pool.cpp:91
        task = {task = {_M_invoker = 0x7f8dcfe83ce0 <_M_invoke>}, promise = {_M_future = {<No data fields>}, _M_storage = {_M_t = {<No data fields>}}}, task_exception = {_M_exception_object = 0x0}}
        lock = {_M_device = 0x564379f8a508, _M_owns = false}
#13 __invoke_impl () at /usr/include/c++/6/functional:210
No locals.
#14 __invoke () at /usr/include/c++/6/functional:251
No locals.
#15 operator() () at /usr/include/c++/6/functional:465
No locals.
#16 _M_invoke () at /usr/include/c++/6/functional:1391
        this = <optimized out>
#17 operator() () at /usr/include/c++/6/functional:1380
        this = <optimized out>
#18 _M_run (this=<optimized out>) at /usr/include/c++/6/thread:197
No locals.
#19 0x00007f8dced78b2f in execute_native_thread_routine () from /tmp/apport_sandbox_gkegru/usr/lib/x86_64-linux-gnu/libstdc++.so.6
No symbol table info available.
#20 0x00007f8dcf8ed6ca in start_thread (arg=0x7f8dc1d1f700) at pthread_create.c:333
        __res = <optimized out>
        pd = 0x7f8dc1d1f700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140246818879232, 5598854712723761678, 0, 140730976679023, 140246818879936, 140246818879232, -5573025242664932850, -5572993777008514546}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#21 0x00007f8dce7e70ff in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:105
No locals.