Unfortunately I can't tell what in shm_access is failing exactly because gdb skips straight from shm.c:314 back to the caller. So that suggests this code path, but I can't verify it:
static int shm_access(ClientPtr client, SHMPERM_TYPE * perm, int readonly) { int uid, gid; mode_t mask; int uidset = 0, gidset = 0; LocalClientCredRec *lcc; if (GetLocalClientCreds(client, &lcc) != -1) { // FALSE ... } /* Otherwise, check everyone else */ mask = S_IROTH; if (!readonly) { mask |= S_IWOTH; } return (SHMPERM_MODE(perm) & mask) == mask ? 0 : -1; } So Xorg _should_ be returning an error, and it is. The problem seems to be that the client (python3 gtk_ui process) has a real uid=0 and effective uid=999. So that allows it to connect to Xorg (normally Xorg rejects root clients), but doesn't allow Xorg to check the client shm permissions. So Xorg rejects the client's attempt at XShmAttach. How any of this relates to scale=200% and why it works at 100%, I'm not sure. We might need to review comment #15 in more detail. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to glib2.0 in Ubuntu. https://bugs.launchpad.net/bugs/1751252 Title: [regression] ubiquity crashed in debconf.py:104 with ValueError: invalid literal for int() with base 10: '' Status in OEM Priority Project: Triaged Status in glib2.0 package in Ubuntu: Invalid Status in ubiquity package in Ubuntu: Triaged Status in glib2.0 source package in Bionic: Invalid Status in ubiquity source package in Bionic: Triaged Bug description: The Ubuntu installer crashes on hiDPI machines (QHD/UHD etc). Although it was working some weeks/months ago, so this is a recent regression. --- https://errors.ubuntu.com/problem/82f7f7e7923663c7b2123c7f1f49af29f6ff4d77 https://errors.ubuntu.com/problem/735a2b847e0eeab6c8a7b954de5110e43889be15 https://errors.ubuntu.com/problem/dcd4c9da5ee0cc6d36324446e0e49d39705c90b7 https://errors.ubuntu.com/problem/cb82f70f9ede07369e8104da9ddf87e28b42257d https://errors.ubuntu.com/problem/84a5563af3d2b85f098da832ece4cb8450bfd524 --- WORKAROUND: 1. Boot into the live session. 2. Settings > Devices > Displays > Scale = 100% 3. Click Apply. 4. Proceed with installation: Click "Install Ubuntu 18.04 LTS". --- Crashed in a VM in the middle of installation. The host is Bionic up to date. From the journal Feb 23 12:52:27 ubuntu kernel: traps: ubiquity[2646] trap int3 ip:7f5a76936961 sp:7ffde5090c50 error:0 in libglib-2.0.so.0.5400.1[7f5a768e6000+111000] Feb 23 12:52:41 ubuntu /install.py[6858]: Exception during installation: Feb 23 12:52:41 ubuntu /install.py[6858]: Traceback (most recent call last): Feb 23 12:52:41 ubuntu /install.py[6858]: File "/usr/share/ubiquity/install.py", line 757, in <module> Feb 23 12:52:41 ubuntu /install.py[6858]: install.run() Feb 23 12:52:41 ubuntu /install.py[6858]: File "/usr/share/ubiquity/install.py", line 135, in run Feb 23 12:52:41 ubuntu /install.py[6858]: self.copy_all() Feb 23 12:52:41 ubuntu /install.py[6858]: File "/usr/share/ubiquity/install.py", line 505, in copy_all Feb 23 12:52:41 ubuntu /install.py[6858]: self.db.progress('SET', 10 + copy_progress) Feb 23 12:52:41 ubuntu /install.py[6858]: File "/usr/lib/python3/dist-packages/debconf.py", line 83, in <lambda> Feb 23 12:52:41 ubuntu /install.py[6858]: lambda *args, **kw: self.command(command, *args, **kw)) Feb 23 12:52:41 ubuntu /install.py[6858]: File "/usr/lib/python3/dist-packages/debconf.py", line 104, in command Feb 23 12:52:41 ubuntu /install.py[6858]: status = int(status) Feb 23 12:52:41 ubuntu /install.py[6858]: ValueError: invalid literal for int() with base 10: '' ProblemType: Crash DistroRelease: Ubuntu 18.04 Package: ubiquity 18.04.1 ProcVersionSignature: Ubuntu 4.13.0-32.35-generic 4.13.13 Uname: Linux 4.13.0-32-generic x86_64 ApportVersion: 2.20.8-0ubuntu10 Architecture: amd64 CasperVersion: 1.388 Date: Fri Feb 23 12:52:28 2018 ExecutablePath: /usr/lib/ubiquity/bin/ubiquity InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- keyboard-configuration/layoutcode=fr keyboard-configuration/variantcode=oss InterpreterPath: /usr/bin/python3.6 LiveMediaBuild: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180222) ProcCmdline: /usr/bin/python3 /usr/lib/ubiquity/bin/ubiquity -d ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash Python3Details: /usr/bin/python3.6, Python 3.6.4+, python3-minimal, 3.6.4-1 PythonDetails: /usr/bin/python2.7, Python 2.7.14+, python-minimal, 2.7.14-4 Signal: 5 SourcePackage: ubiquity StacktraceTop: ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6 ?? () from /usr/lib/x86_64-linux-gnu/libX11.so.6 _XEventsQueued () from /usr/lib/x86_64-linux-gnu/libX11.so.6 XPending () from /usr/lib/x86_64-linux-gnu/libX11.so.6 ?? () from /usr/lib/x86_64-linux-gnu/libgdk-3.so.0 Title: ubiquity crashed with signal 5 in _XEventsQueued() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1751252/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp