I am using gnome-connections to connect to a server that offers an RDP service. Both the client and server run Fedora 42. I loosely followed Vladislav Grigoryev's instructions at https://discourse.gnome.org/t/headless-remote-desktop-setup-process/20411/2 to configure the server. The server is running gdm-48.0-3.fc42.x86_64. Watching the system logs seems to indicate GDM is causing a segmentation fault. Here is one such log: Process 8156 (gdm) of user 0 dumped core. Module /usr/bin/gdm from rpm gdm-48.0-3.fc42.x86_64 Module libnss_systemd.so.2 from rpm systemd-257.6-1.fc42.x86_64 Module libnss_sss.so.2 from rpm sssd-2.10.2-3.fc42.x86_64 Module libblkid.so.1 from rpm util-linux-2.40.4-7.fc42.x86_64 Module libudev.so.1 from rpm systemd-257.6-1.fc42.x86_64 Module libcrypt.so.2 from rpm libxcrypt-4.4.38-7.fc42.x86_64 Module libselinux.so.1 from rpm libselinux-3.8-1.fc42.x86_64 Module libmount.so.1 from rpm util-linux-2.40.4-7.fc42.x86_64 Module libz.so.1 from rpm zlib-ng-2.2.4-3.fc42.x86_64 Module libgmodule-2.0.so.0 from rpm glib2-2.84.2-1.fc42.x86_64 Module libpcre2-8.so.0 from rpm pcre2-10.45-1.fc42.x86_64 Module libffi.so.8 from rpm libffi-3.4.6-5.fc42.x86_64 Module libcap.so.2 from rpm libcap-2.73-2.fc42.x86_64 Module libgudev-1.0.so.0 from rpm libgudev-238-7.fc42.x86_64 Module libXau.so.6 from rpm libXau-1.0.12-2.fc42.x86_64 Module libxcb.so.1 from rpm libxcb-1.17.0-5.fc42.x86_64 Module libjson-glib-1.0.so.0 from rpm json-glib-1.10.6-2.fc42.x86_64 Module libaccountsservice.so.0 from rpm accountsservice-23.13.9-8.fc42.x86_64 Module libgio-2.0.so.0 from rpm glib2-2.84.2-1.fc42.x86_64 Module libglib-2.0.so.0 from rpm glib2-2.84.2-1.fc42.x86_64 Module libgobject-2.0.so.0 from rpm glib2-2.84.2-1.fc42.x86_64 Module libsystemd.so.0 from rpm systemd-257.6-1.fc42.x86_64 Stack trace of thread 8156: #0 0x00007f11df28e548 g_logv (libglib-2.0.so.0 + 0x46548) #1 0x00007f11df28e803 g_log (libglib-2.0.so.0 + 0x46803) #2 0x000055f02f636f33 get_fallback_session_name (/usr/bin/gdm + 0x29f33) #3 0x000055f02f6400f5 gdm_session_start_session (/usr/bin/gdm + 0x330f5) #4 0x00007f11decb9056 ffi_call_unix64 (libffi.so.8 + 0x8056) #5 0x00007f11decb4d08 ffi_call_int.lto_priv.0 (libffi.so.8 + 0x3d08) #6 0x00007f11decb770e ffi_call (libffi.so.8 + 0x670e) #7 0x00007f11df3aa93c g_cclosure_marshal_generic_va (libgobject-2.0.so.0 + 0xd93c) #8 0x00007f11df3c3c52 signal_emit_valist_unlocked (libgobject-2.0.so.0 + 0x26c52) #9 0x00007f11df3c3d68 g_signal_emit_valist (libgobject-2.0.so.0 + 0x26d68) #10 0x00007f11df3c3e23 g_signal_emit (libgobject-2.0.so.0 + 0x26e23) #11 0x000055f02f63c2f1 on_opened (/usr/bin/gdm + 0x2f2f1) #12 0x00007f11df0f3e7c g_task_return_now (libgio-2.0.so.0 + 0x7ae7c) #13 0x00007f11df0f9590 g_task_return (libgio-2.0.so.0 + 0x80590) #14 0x00007f11df168567 reply_cb (libgio-2.0.so.0 + 0xef567) #15 0x00007f11df0f3e7c g_task_return_now (libgio-2.0.so.0 + 0x7ae7c) #16 0x00007f11df0f9590 g_task_return (libgio-2.0.so.0 + 0x80590) #17 0x00007f11df15e932 g_dbus_connection_call_done (libgio-2.0.so.0 + 0xe5932) #18 0x00007f11df0f3e7c g_task_return_now (libgio-2.0.so.0 + 0x7ae7c) #19 0x00007f11df0f3eb5 complete_in_idle_cb (libgio-2.0.so.0 + 0x7aeb5) #20 0x00007f11df28ee0d g_idle_dispatch (libglib-2.0.so.0 + 0x46e0d) #21 0x00007f11df288880 g_main_context_dispatch_unlocked.lto_priv.0 (libglib-2.0.so.0 + 0x40880) #22 0x00007f11df2917a8 g_main_context_iterate_unlocked.isra.0 (libglib-2.0.so.0 + 0x497a8) #23 0x00007f11df291a4f g_main_loop_run (libglib-2.0.so.0 + 0x49a4f) #24 0x000055f02f612b18 main (/usr/bin/gdm + 0x5b18) #25 0x00007f11dedc05f5 __libc_start_call_main (libc.so.6 + 0x35f5) #26 0x00007f11dedc06a8 __libc_start_main@@GLIBC_2.34 (libc.so.6 + 0x36a8) #27 0x000055f02f612e85 _start (/usr/bin/gdm + 0x5e85) Stack trace of thread 8159: #0 0x00007f11dee366c2 __syscall_cancel_arch (libc.so.6 + 0x796c2) #1 0x00007f11dee2a9da __internal_syscall_cancel (libc.so.6 + 0x6d9da) #2 0x00007f11dee2aa24 __syscall_cancel (libc.so.6 + 0x6da24) #3 0x00007f11deea4176 ppoll (libc.so.6 + 0xe7176) #4 0x00007f11df291890 g_main_context_iterate_unlocked.isra.0 (libglib-2.0.so.0 + 0x49890) #5 0x00007f11df291a4f g_main_loop_run (libglib-2.0.so.0 + 0x49a4f) #6 0x00007f11df160272 gdbus_shared_thread_func.lto_priv.0 (libgio-2.0.so.0 + 0xe7272) #7 0x00007f11df2be862 g_thread_proxy (libglib-2.0.so.0 + 0x76862) #8 0x00007f11dee2e1d4 start_thread (libc.so.6 + 0x711d4) #9 0x00007f11deeb0cec __clone3 (libc.so.6 + 0xf3cec) Stack trace of thread 8165: #0 0x00007f11deeaea8d syscall (libc.so.6 + 0xf1a8d) #1 0x00007f11df2b52ab g_cond_wait_until (libglib-2.0.so.0 + 0x6d2ab) #2 0x00007f11df251ded g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x9ded) #3 0x00007f11df2bfa9a g_thread_pool_thread_proxy (libglib-2.0.so.0 + 0x77a9a) #4 0x00007f11df2be862 g_thread_proxy (libglib-2.0.so.0 + 0x76862) #5 0x00007f11dee2e1d4 start_thread (libc.so.6 + 0x711d4) #6 0x00007f11deeb0cec __clone3 (libc.so.6 + 0xf3cec) Stack trace of thread 8158: #0 0x00007f11dee366c2 __syscall_cancel_arch (libc.so.6 + 0x796c2) #1 0x00007f11dee2a9da __internal_syscall_cancel (libc.so.6 + 0x6d9da) #2 0x00007f11dee2aa24 __syscall_cancel (libc.so.6 + 0x6da24) #3 0x00007f11deea4176 ppoll (libc.so.6 + 0xe7176) #4 0x00007f11df291890 g_main_context_iterate_unlocked.isra.0 (libglib-2.0.so.0 + 0x49890) #5 0x00007f11df291953 g_main_context_iteration (libglib-2.0.so.0 + 0x49953) #6 0x00007f11df2919a1 glib_worker_main (libglib-2.0.so.0 + 0x499a1) #7 0x00007f11df2be862 g_thread_proxy (libglib-2.0.so.0 + 0x76862) #8 0x00007f11dee2e1d4 start_thread (libc.so.6 + 0x711d4) #9 0x00007f11deeb0cec __clone3 (libc.so.6 + 0xf3cec) Stack trace of thread 8157: #0 0x00007f11deeaea8d syscall (libc.so.6 + 0xf1a8d) #1 0x00007f11df2b43eb g_cond_wait (libglib-2.0.so.0 + 0x6c3eb) #2 0x00007f11df251e2c g_async_queue_pop_intern_unlocked (libglib-2.0.so.0 + 0x9e2c) #3 0x00007f11df2bed14 g_thread_pool_spawn_thread (libglib-2.0.so.0 + 0x76d14) #4 0x00007f11df2be862 g_thread_proxy (libglib-2.0.so.0 + 0x76862) #5 0x00007f11dee2e1d4 start_thread (libc.so.6 + 0x711d4) #6 0x00007f11deeb0cec __clone3 (libc.so.6 + 0xf3cec) ELF object binary architecture: AMD x86-64
I was able to do some more analysis: GDB showed the error is occurring in GDM's get_fallback_session_name function. The process is terminating with an error because GDM cannot find a supported session type. For some reason, self->supported_session_types is {"x11", 0x00} in get_fallback_session_name. The lack of "wayland" is odd. Things started working after I installed the gnome-session-xsession package. I am not sure why "wayland" is not a supported session type when GDM runs. The reason I said this is odd is that Fedora went so far as to disable X11 support in GDM in Fedora 42 for a while. I think the community decided this was too aggressive or at least did not follow the official change process. Instead, removing X11 support is proposed for Fedora 43 (https://fedoraproject.org/wiki/Changes/WaylandOnlyGNOME). Anyway, in this case I would prefer Wayland, and I am unsure what is going wrong in GDM that it is not supported.
I am starting to see this as GDM being unable to run without a local display. I submitted an upstream issue: https://gitlab.gnome.org/GNOME/gdm/-/issues/1046