I would like to add some info that may help to narrow the problem. I have had this crash in PCManFM since i upgraded ubuntu from 16.04 to 18.04 but the same bug manifest in Geany and Chromium as well. The bug could hit PCManFM within a few clicks opening directories and then clicking on a file or can take hours to show up. In the case of Chromium it usually hit at the launch of the browser.
I rebuilt the LibX11 with the supposedly fix mentioned by Tycho Kircher and apparently this has not fixed the problem but the crash is now without the Assertion `!xcb_xlib_threads_sequence_lost' failed. I installed only these packages: * libx11-xcb1_1.6.4-3ubuntu0.2_amd64.deb * libx11-xcb-dev_1.6.4-3ubuntu0.2_amd64.deb lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 18.04.4 LTS Release: 18.04 Codename: bionic -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1782984 Title: Assertion `!xcb_xlib_threads_sequence_lost' failed with multiple applications To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libx11/+bug/1782984/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
