OK, So I tried to debug this on 17.04 with the mir demos. What happens is that while the Mir server seems to run fine, when the EGL mir clients import a surface from the mir server (using fds / prime) they typecast the XRGB surface from the mir server to an ARGB surface, which the svga gallium driver doesn't like that and it returns an error.
That error is never caught in the mir platform EGL layer and when the corresponding "bo" is dereferenced, the mir platform EGL layer instead dereferences NULL, which is the error code... So I'd say this is a combination of two Mir errors: One illegal typecast and one failure to check for errors. As a side note, it would be possible for the svga driver to implement a workaround and not error in this case, but while real hardware may be more forgiving in this case, the surface that the mir client thinks is an argb surface will still be an xrgb surface and any operation involving the alpha channel will yield unexpected results so IMHO this needs to be fixed in the MIR EGL layer: Offending code: (platform_mir.c) static struct gbm_bo *create_gbm_bo_from_buffer(struct gbm_device* gbm_dev, MirBufferPackage *package) { struct gbm_import_fd_data data; data.fd = package->fd[0]; data.width = package->width; data.height = package->height; data.format = GBM_FORMAT_ARGB8888; /* TODO: Use mir surface format */ <= HERE! data.stride = package->stride; return gbm_bo_import(gbm_dev, GBM_BO_IMPORT_FD, &data, GBM_BO_USE_RENDERING); } /Thomas -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/1560498 Title: Unity8 using vmwgfx_dri.so crashed in mir::graphics::nested::detail::DisplayBuffer::make_current() -> eglMakeCurrent() -> ... -> dri2_image_get_buffers() [platform_mir.c:138] Status in Mir: New Status in mesa package in Ubuntu: Confirmed Status in mir package in Ubuntu: Confirmed Status in unity8 package in Ubuntu: Invalid Bug description: The Ubuntu Error Tracker has been receiving reports about a problem regarding unity8. This problem was most recently seen with version 8.11+16.04.20160310.4-0ubuntu1, the problem page at https://errors.ubuntu.com/problem/7e3f860c1afbbc114bf73f9d7a2966209a25093d contains more details. To manage notifications about this bug go to: https://bugs.launchpad.net/mir/+bug/1560498/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp