x11-base/xorg-server with USE unwind and FEATURES splitdebug doesn't find unwind information. I didn't test yet whether removing splitdebug from FEATURES solves the problem. $ emerge -1Op x11-base/xorg-server [...] [ebuild R ] x11-base/xorg-server-1.20.10:0/1.20.10::gentoo USE="elogind ipv6 kdrive udev unwind xorg xvfb -debug -dmx -doc -libressl -minimal (-selinux) -suid -systemd -wayland -xcsecurity -xephyr -xnest" 0 KiB [...] $ less /var/log/Xorg.0.log.old [...] [2538311.626] (EE) Backtrace: [2538311.632] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.633] (EE) 0: /usr/bin/X (?+0x0) [0x55ec86b6bb38] [2538311.633] (EE) 1: /lib64/libpthread.so.0 (funlockfile+0x50) [0x7f787d2ddef0] [2538311.634] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.634] (EE) 2: /usr/bin/X (?+0x0) [0x55ec86adb118] [2538311.634] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.634] (EE) 3: /usr/bin/X (?+0x0) [0x55ec86b49e4d] [2538311.634] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.634] (EE) 4: /usr/bin/X (?+0x0) [0x55ec86b49812] [2538311.635] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.635] (EE) 5: /usr/bin/X (?+0x0) [0x55ec86a36767] [2538311.635] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.635] (EE) 6: /usr/bin/X (?+0x0) [0x55ec86b5ecb6] [2538311.635] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.635] (EE) 7: /usr/bin/X (?+0x0) [0x55ec86a0b820] [2538311.635] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.636] (EE) 8: /usr/bin/X (?+0x0) [0x55ec869d2670] [2538311.636] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.636] (EE) 9: /usr/bin/X (?+0x0) [0x55ec869d85e5] [2538311.636] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.636] (EE) 10: /usr/bin/X (?+0x0) [0x55ec869dddf3] [2538311.641] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.641] (EE) 11: /lib64/libc.so.6 (?+0x0) [0x7f787d0ff01e] [2538311.641] (EE) unw_get_proc_name failed: no unwind info found [-10] [2538311.641] (EE) 12: /usr/bin/X (?+0x0) [0x55ec869c1f8a] [2538311.641] (EE) [2538311.641] (EE) Segmentation fault at address 0x0 I reported the but causing the segfault already 4 month ago directly to freedesktop.org, this Gentoo bug report is only about the unwind failure. https://gitlab.freedesktop.org/xorg/xserver/-/issues/1080 FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs clean-logs collision-protect compressdebug config-protect-if-modified distlocks ebuild-locks fixlafiles installsources ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-fetch pid-sandbox preserve-libs protect-owned qa-unresolved-soname-deps sandbox sfperms splitdebug strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"