** Summary changed: - dbus-launch freezes for unknown reason at session start + dbus-launch hangs at session start waiting on socket output in libxcb
** Description changed: Ubuntu 8.04 It is not reproducible (I don't know when it happens). But it happens often enough. dbus-launch can't be killed with SIGTERM (nor it dies when X session is killed, nor after Ctrl-Alt-Backspace) when it happens and seem to hang on some synchronization routine IIRC from the last time I tried to debug the issue. I installed dbgsyms this times and will try to debug dbus-launch next time it happens. BTW, isn't dbus-launch supposed to exit after dbus-daemon is started (for the user session)? + + [Workaround] + kill the "dbus-launch --sh-syntax --exit-with-session" with signal 9. This allows the login process to finish. + + Or else just reboot several times. It seems to be a race condition and + some people see it affecting login only intermittently. + + [Background] + Due to various problems in the venerable xlib, Xorg upstream created the "X C-Language Bindings" (XCB). Debian and Ubuntu switched to an xcb-enabled libx11 in the Hardy timeframe. Prior to this, a known issue with Java (bug LP: #86103) prevented us from shipping XCB in Xorg. A patch to enable 'sloppy locking' solved the java issue and allowed Ubuntu to follow Debian in shipping with this enabled in Hardy. + + [Next Steps] + XCB is a new technology and as such is a prominent suspect, however we've not yet proven it as the culprit beyond a shadow of doubt. A non-XCB libx11 package has been prepared for testing, and so the first step is to demonstrate conclusively that the issue is completely absent with that package. + + Since Hardy is an LTS, it is important that we have this issue fixed, + however disabling XCB in libx11 maybe too short sighted; doing so could + just unpredictably generate regressions in other packages, and it really + only sweeps the problem under the rug for us to re-encounter later. + Much better would be to work with upstream to get this issue resolved + definitively. Going forward, as more X client applications start + depending on XCB, having it available in Hardy will be of obvious + benefit. But if we can show that a non-XCB libx11 resolves the issue, + and no other viable workaround or solution comes to light, we may have + no choice than to fall back to that. -- dbus-launch hangs at session start waiting on socket output in libxcb https://bugs.launchpad.net/bugs/232364 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
