Package: xserver-xephyr Version: 1:1.19.6-1 Severity: important I use Xephyr to play Sid Meier's Alpha Centauri (yes, people still play that), and this requires disabling its Composite extension (or the game hangs). Unfortunately, on my amd64 machine with Xephyr version 1.19.6 this throws an error (used to work with version 1.19.5):
$ Xephyr :1 -screen 800x600 -extension Composite Xephyr: ../../../../include/privates.h:122: dixGetPrivateAddr: Assertion `key- >initialized' failed. (EE) (EE) Backtrace: (EE) 0: Xephyr (xorg_backtrace+0x4d) [0x5608257337bd] (EE) 1: Xephyr (0x56082556d000+0x1ca559) [0x560825737559] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f0b03af6000+0x12180) [0x7f0b03b08180] (EE) 3: /lib/x86_64-linux-gnu/libc.so.6 (gsignal+0x110) [0x7f0b037746a0] (EE) 4: /lib/x86_64-linux-gnu/libc.so.6 (abort+0x1c7) [0x7f0b03775cf7] (EE) 5: /lib/x86_64-linux-gnu/libc.so.6 (0x7f0b03740000+0x2cfca) [0x7f0b0376cfca] (EE) 6: /lib/x86_64-linux-gnu/libc.so.6 (0x7f0b03740000+0x2d042) [0x7f0b0376d042] (EE) 7: Xephyr (0x56082556d000+0x3c252) [0x5608255a9252] (EE) 8: Xephyr (0x56082556d000+0x1c1c1f) [0x56082572ec1f] (EE) 9: Xephyr (0x56082556d000+0x12c667) [0x560825699667] (EE) 10: Xephyr (0x56082556d000+0x12bcc5) [0x560825698cc5] (EE) 11: Xephyr (0x56082556d000+0x12b115) [0x560825698115] (EE) 12: Xephyr (InitExtensions+0x3d) [0x56082562ce2d] (EE) 13: Xephyr (0x56082556d000+0x7c93f) [0x5608255e993f] (EE) 14: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xea) [0x7f0b03760f2a] (EE) 15: Xephyr (_start+0x2a) [0x5608255a92fa] (EE) (EE) Fatal server error: (EE) Caught signal 6 (Aborted). Server aborting (EE) Withour "-extension Composite" Xephyr starts, but unfortunately I can't play the game. Given that this is the only reason I use Xephyr (and I suspect that applies to many people as well), I think this bug qualifies as "important"...