Xpra: Ticket #2764: Xdummy crashes as soon as xpra connects

Description: Xdummy crashes as soon as xpra connects.

I am trying Xpra on a kubuntu eoan (19.10) system. On this kind of system I have successfully used xpra many times in the past. However, I am now encountering crashes that make it impossible to use it. My system is a laptop with an intel i7-10510U cpu (comet lake) and integrated Intel HD graphics 620 (I believe).

For testing purposes I am attempting to use Xpra locally

xpra start :101
DISPLAY=:101 xterm &
xpra attach ssh:localhost:101

at this point, the xterm is briefly shown but xdummy crashes right after. Using --opengl=no does not seem to make any difference.

Any hint?

System: Xpra version, platform and host information
argv                             : ['/usr/bin/xpra', 'bug-report']
config                           : {'clipboard': 'yes', 'clipboard-direction': 'both', 'notifications': 'yes', 'tray': 'yes', 'system-tray': 'yes', 'pings': '5', 'remote-logging': 'both', 'mmap': 'yes', 'mmap-group': 'auto', 'socket-permissions': '600', 'sharing': 'auto', 'lock': 'auto', 'compressors': 'lz4, lzo, zlib, brotli', 'compression_level': '1', 'packet-encoders': 'rencode, bencode, yaml', 'socket-dirs': ['/run/user/$UID/xpra', '/run/xpra'], 'idle-timeout': '0', 'server-idle-timeout': '0', 'bandwidth-limit': 'auto', 'ssl-key': '', 'ssl-cert': '', 'ssl-client-verify-mode': 'optional', 'ssl-server-verify-mode': 'required', 'ssl-check-hostname': 'off', 'ssl-server-hostname': 'localhost', 'ssl-verify-flags': 'X509_STRICT', 'ssl-ciphers': 'DEFAULT', 'ssl-options': 'ALL,NO_COMPRESSION', 'file-transfer': 'auto', 'open-url': 'auto', 'file-size-limit': '100', 'open-files': 'auto', 'printing': 'yes', 'lpadmin': '/usr/sbin/lpadmin', 'add-printer-options': ['-E', '-o printer-is-shared=false', '-u allow:$USER'], 'lpinfo': '/usr/sbin/lpinfo', 'postscript-printer': 'drv:///sample.drv/generic.ppd', 'pdf-printer': '/usr/share/ppd/cupsfilters/Generic-PDF_Printer-PDF.ppd', 'speaker': 'on', 'microphone': 'off', 'av-sync': 'on', 'encodings': 'all', 'encoding': 'auto', 'video-encoders': 'all', 'csc-modules': 'all', 'video-decoders': 'all', 'video-scaling': 'auto', 'quality': 'auto', 'min-quality': '30', 'speed': 'auto', 'min-speed': '30', 'auto-refresh-delay': '0.15', 'pixel-depth': '0', 'webcam': 'auto', 'opengl': 'probe', 'challenge-handlers': 'all', 'title': '@title@ on @hostname@', 'ssh': 'auto', 'mousewheel': 'on', 'window-close': 'auto', 'desktop-scaling': 'auto', 'desktop-fullscreen': 'no', 'keyboard-sync': 'yes', 'shortcut-modifiers': 'auto', 'key-shortcut': ['Control+Menu:toggle_keyboard_grab', 'Shift+Menu:toggle_pointer_grab', 'Shift+F11:toggle_fullscreen', '#+F1:show_menu', '#+F2:show_start_new_command', '#+F3:show_bug_report', '#+F4:quit', '#+F5:increase_quality', '#+F6:decrease_quality', '#+F7:increase_speed', '#+F8:decrease_speed', '#+F10:magic_key', '#+F11:show_session_info', '#+F12:toggle_debug', '#+plus:scaleup', '#+minus:scaledown', '#+underscore:scaledown', '#+KP_Add:scaleup', '#+KP_Subtract:scaledown', '#+KP_Multiply:scalereset', '#+bar:scalereset', '#+question:scalingoff'], 'mdns': 'yes', 'bind': 'auto', 'min-port': '1024', 'ssl': 'auto', 'html': 'auto', 'rfb-upgrade': '5', 'wm-name': 'Xpra', 'input-method': 'none', 'sync-xvfb': '0', 'fake-xinerama': 'no', 'xvfb': '/usr/lib/xorg/Xorg -noreset -novtswitch -nolisten tcp +extension GLX +extension RANDR +extension RENDER -auth $XAUTHORITY -logfile ${XPRA_LOG_DIR}/Xorg.${DISPLAY}.log -configdir ${XDG_RUNTIME_DIR}/xpra/xorg.conf.d/$PID -config /etc/xpra/xorg.conf', 'log-dir': 'auto', 'log-file': '$DISPLAY.log', 'start-via-proxy': 'no', 'start-env': ["#avoid Ubuntu's global menu, which is a mess and cannot be forwarded:", 'UBUNTU_MENUPROXY=', 'QT_X11_NO_NATIVE_MENUBAR=1', "#fix for MainSoft's MainWin buggy window management:", 'MWNOCAPTURE=true', 'MWNO_RIT=true', 'MWWM=allwm', '#force GTK3 applications to use X11 so we can intercept them:', 'GDK_BACKEND=x11', '#force Qt applications to use X11 so we can intercept them:', 'QT_QPA_PLATFORM=xcb', '#overlay scrollbars complicate things:GTK_OVERLAY_SCROLLING=0', '#some versions of GTK3 honour this option, sadly not all:', 'GTK_CSD=0', '#silence some AT-SPI and atk-bridge warnings:', 'NO_AT_BRIDGE=1'], 'exit-with-children': 'no', 'dbus-launch': 'dbus-launch --sh-syntax --close-stderr', 'dbus-control': 'yes', 'dbus-proxy': 'yes', 'start-new-commands': 'yes', 'pulseaudio': 'auto', 'pulseaudio-command': 'pulseaudio --start -n --daemonize=false --system=false --exit-idle-time=-1 --load=module-suspend-on-idle \'--load=module-null-sink sink_name="Xpra-Speaker" sink_properties=device.description="Xpra\\ Speaker"\' \'--load=module-null-sink sink_name="Xpra-Microphone" sink_properties=device.description="Xpra\\ Microphone"\' \'--load=module-native-protocol-unix socket=$XPRA_PULSE_SERVER\' --load=module-dbus-protocol --load=module-x11-publish --log-level=2 --log-target=stderr --enable-memfd=no', 'pulseaudio-configure-commands': ['pactl set-default-sink Xpra-Speaker', 'pactl set-default-source Xpra-Microphone.monitor'], 'systemd-run': 'auto', 'proxy-start-sessions': 'True', 'proxy-video-encoders': 'none'}
display                          : {'root-size': (1920, 1080), 'screens': {0: {'root': (x=0, y=0, width=1920, height=1080), 'name': ':0.0', 'width': 1920, 'height': 1080, 'width_mm': 506, 'height_mm': 285, 'resolution': 96, 'primary_monitor': 0, 'monitors': 1, 'monitor': {0: {'x': 0, 'y': 0, 'width': 1920, 'height': 1080, 'plug_name': 'eDP-1', 'scale_factor': 1, 'width_mm': 309, 'height_mm': 174, 'workarea': {'x': 0, 'y': 0, 'width': 1920, 'height': 1044}}}, 'fontoptions': {'antialias': 'subpixel', 'hint_metrics': 'on', 'hint_style': 'slight', 'subpixel_order': 'RGB'}, 'visual': {'rgba': {'bits_per_rgb': 8, 'byte_order': 'LSB', 'colormap_size': 256, 'depth': 32, 'red_pixel_details': (mask=16711680, shift=16, precision=8), 'green_pixel_details': (mask=65280, shift=8, precision=8), 'blue_pixel_details': (mask=255, shift=0, precision=8), 'visual_type': 'TRUE_COLOR'}, 'system_visual': {'bits_per_rgb': 8, 'byte_order': 'LSB', 'colormap_size': 256, 'depth': 24, 'red_pixel_details': (mask=16711680, shift=16, precision=8), 'green_pixel_details': (mask=65280, shift=8, precision=8), 'blue_pixel_details': (mask=255, shift=0, precision=8), 'visual_type': 'TRUE_COLOR'}}, 'settings': {'enable-event-sounds': '', 'icon-theme-name': '', 'sound-theme-name': '', 'theme-name': '', 'antialias': 1, 'dpi': 98304, 'hinting': 1, 'hintstyle': 'hintslight', 'rgba': 'rgb'}}}, 'name': ':0', 'pointer': (919, 906), 'devices': 4, 'default_cursor_size': 22, 'maximal_cursor_size': (width=128, height=128), 'pointer_is_grabbed': False, 'root': (x=0, y=0, width=1920, height=1080), 'supports': {'composite': True, 'cursor_alpha': True, 'cursor_color': True, 'selection_notification': True, 'clipboard_persistence': False, 'shapes': True}, 'device': {'master': {0: 'Virtual core keyboard', 1: 'Virtual core pointer'}, 'slave': {0: 'TECKNET BM306 Mouse', 1: 'SynPS/2 Synaptics TouchPad', 2: 'AT Translated Set 2 keyboard', 3: 'Intel HID events', 4: 'Chicony USB2.0 Camera: Chicony ', 5: 'Sleep Button', 6: 'Power Button', 7: 'Video Bus', 8: 'Power Button', 9: 'Virtual core XTEST keyboard', 10: 'Virtual core XTEST pointer'}, 'floating': {}}}
env                              : environ({'SHELL': '/bin/bash', 'SESSION_MANAGER': 'local/jakmandolino:@/tmp/.ICE-unix/1596,unix/jakmandolino:/tmp/.ICE-unix/1596', 'WINDOWID': '62914567', 'COLORTERM': 'truecolor', 'XDG_CONFIG_DIRS': '/etc/xdg/xdg-plasma:/etc/xdg:/usr/share/kubuntu-default-settings/kf5-settings', 'XDG_SESSION_PATH': '/org/freedesktop/DisplayManager/Session1', 'LANGUAGE': '', 'MANDATORY_PATH': '/usr/share/gconf/plasma.mandatory.path', 'LC_ADDRESS': 'it_IT.UTF-8', 'LC_NAME': 'it_IT.UTF-8', 'SSH_AUTH_SOCK': '/tmp/ssh-j8IsXywRluTE/agent.1490', 'SHELL_SESSION_ID': 'f8e4947bfa354b778363a22090a762fa', 'DESKTOP_SESSION': 'plasma', 'LC_MONETARY': 'it_IT.UTF-8', 'SSH_AGENT_PID': '1533', 'XDG_SEAT': 'seat0', 'PWD': '/home/callegar', 'XDG_SESSION_DESKTOP': 'KDE', 'LOGNAME': 'callegar', 'XDG_SESSION_TYPE': 'x11', 'MANPATH': ':/usr/local/texlive/2020/texmf-dist/doc/man/', 'GPG_AGENT_INFO': '/run/user/1000/gnupg/S.gpg-agent:0:1', 'XAUTHORITY': '/home/callegar/.Xauthority', 'HOME': '/home/callegar', 'LC_PAPER': 'it_IT.UTF-8', 'LANG': 'en_US.UTF-8', 'LS_COLORS': 'rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:', 'XDG_CURRENT_DESKTOP': 'KDE', 'KONSOLE_DBUS_SERVICE': ':1.349', 'KONSOLE_DBUS_SESSION': '/Sessions/2', 'PROFILEHOME': '', 'BIBINPUTS': '/home/callegar/Documents/BibFiles:./', 'XDG_SEAT_PATH': '/org/freedesktop/DisplayManager/Seat0', 'PERL5LIB': '/home/callegar/lib/perl5/:/home/callegar/share/perl5', 'KONSOLE_VERSION': '191203', 'KDE_SESSION_UID': '1000', 'INFOPATH': '/usr/local/texlive/2020/texmf-dist/doc/info/', 'LESSCLOSE': '/usr/bin/lesspipe %s %s', 'XDG_SESSION_CLASS': 'user', 'TERM': 'xterm-256color', 'LC_IDENTIFICATION': 'it_IT.UTF-8', 'DEFAULTS_PATH': '/usr/share/gconf/plasma.default.path', 'LESSOPEN': '| /usr/bin/lesspipe %s', 'USER': 'callegar', 'COLORFGBG': '0;15', 'KDE_SESSION_VERSION': '5', 'PAM_KWALLET5_LOGIN': '/run/user/1000/kwallet5.socket', 'DISPLAY': ':0', 'SHLVL': '1', 'LC_TELEPHONE': 'it_IT.UTF-8', 'CVS_RSH': 'ssh', 'LC_MEASUREMENT': 'it_IT.UTF-8', 'XDG_VTNR': '1', 'XDG_SESSION_ID': '3', 'LD_LIBRARY_PATH': '/usr/local/lib:/home/callegar/lib:/home/callegar/lib32', 'XDG_RUNTIME_DIR': '/run/user/1000', 'LC_TIME': 'it_IT.UTF-8', 'QT_AUTO_SCREEN_SCALE_FACTOR': '0', 'XCURSOR_THEME': 'breeze_cursors', 'XDG_DATA_DIRS': '/usr/share/plasma:/usr/local/share:/usr/share:/var/lib/snapd/desktop', 'KDE_FULL_SESSION': 'true', 'PATH': '/home/callegar/.local/bin:/home/callegar/bin:/usr/local/texlive/2020/bin/x86_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin:/var/lib/snapd/snap/bin', 'DBUS_SESSION_BUS_ADDRESS': 'unix:path=/run/user/1000/bus', 'LC_NUMERIC': 'it_IT.UTF-8', 'OLDPWD': '/var/crash', 'KONSOLE_DBUS_WINDOW': '/Windows/1', '_': '/usr/bin/xpra', 'GDK_SCALE': '1', 'GTK_CSD': '0'})
exec_prefix                      : /usr
executable                       : /usr/bin/python3
gtk                              : {'gobject': {'version': '2.0'}, 'gi': {'version': '3.34.0'}, 'gtk': {'version': '3.12.24'}, 'gdk': {'version': '3.0'}, 'pixbuf': {'version': '2.40.0'}, 'pygtk': {'version': 'n/a'}, 'glib': {'version': '2.0.62'}, 'cairo': {'version': (1, 16, 2)}, 'pango': {'version': '1.42.3'}}
gui                              : {'native-clipboard': 'xpra.x11.gtk_x11.clipboard.X11Clipboard', 'native_tray_menu_helper': 'None', 'native_trays': ['AppindicatorTray'], 'native_system_trays': [], 'system_bell': 'system_bell', 'native_notifiers': ['DBUS_Notifier_factory', 'PyNotify_Notifier'], 'wm_name': 'KWin', 'workarea': (0, 0, 1920, 1044), 'workareas': [], 'desktops': 4, 'desktop_names': ['Desktop 1', 'Desktop 2', 'Desktop 3', 'Desktop 4'], 'session-type': 'x11', 'vertical-refresh': 60, 'fixed_cursor_size': (-1, -1), 'cursor_size': 0, 'icon_size': 16, 'mouse': {}, 'double_click': {'time': -1, 'distance': (-1, -1)}, 'dpi': {'x': 96, 'y': 96}, 'antialias': {}, 'icc': {}, 'display-icc': {}, 'window_frame': {}, 'can_access_display': True}
host                             : {'pid': 6526, 'byteorder': 'little', 'python': {'bits': 64, 'full_version': '3.7.5 (default, Apr 19 2020, 20:18:17) \n[GCC 9.2.1 20191008]', 'version': '3.7.5'}, 'hostname': 'XXXXXXXXXX', 'uid': 1000, 'gid': 1000}
path                             : ['/usr/bin', '/usr/lib/python37.zip', '/usr/lib/python3.7', '/usr/lib/python3.7/lib-dynload', '/home/callegar/.local/lib/python3.7/site-packages', '/usr/local/lib/python3.7/dist-packages', '/usr/lib/python3/dist-packages']
paths                            : {'install': {'prefix': '/usr'}, 'default_conf': {'dirs': []}, 'system_conf': {'dirs': ['/etc/xpra', '/usr/local/etc/xpra', '/etc/xdg/xdg-plasma/xpra', '/etc/xdg/xpra', '/usr/share/kubuntu-default-settings/kf5-settings/xpra']}, 'ssh_conf': {'dirs': ['/etc/ssh', '/usr/local/etc/ssh', '~/.ssh', '~/ssh']}, 'user_conf': {'dirs': ['~/.config/xpra', '~/.xpra']}, 'socket': {'dirs': ['/run/user/$UID/xpra', '/run/xpra']}, 'log': {'dirs': ['/run/user/$UID/xpra', '/tmp']}, 'download': {'dir': '~/Downloads'}, 'libexec': {'dir': '/usr/lib'}, 'mmap': {'dir': '/run/user/$UID/xpra'}, 'xpra-tmp': {'dir': '/run/user/$UID/xpra/tmp'}, 'xpra-module': '/usr/lib/python3/dist-packages/xpra/', 'app': {'default': {'dir': '/usr/share/xpra'}}, 'desktop-background': ['/usr/share/backgrounds/images/default.png', '/usr/share/backgrounds/images/*default*.png', '/usr/share/backgrounds/*default*png', '/usr/share/backgrounds/gnome/adwaita*.jpg', '/usr/share/backgrounds/images/*jpg'], 'ssh-known-hosts': ('~/.ssh/known_hosts', '~/ssh/known_hosts'), 'resources': '/usr/share/xpra', 'icons': '/usr/share/xpra/icons', 'home': '/home/callegar', 'xpra_command': ['python3.7', '/usr/bin/xpra'], 'nodock_command': ['python3.7', '/usr/bin/xpra'], 'sound_command': ['python3.7', '/usr/bin/xpra'], 'sshpass_command': None, 'python-execfile': ['python3']}
platform                         : {'linux_distribution': ('Ubuntu', '19.10', 'eoan'), '': 'linux', 'name': 'Linux Ubuntu 19.10 eoan', 'release': '5.3.0-51-generic', 'sysrelease': '5.3.0-51-generic', 'platform': 'Linux-5.3.0-51-generic-x86_64-with-Ubuntu-19.10-eoan', 'machine': 'x86_64', 'architecture': ('64bit', 'ELF'), 'processor': 'Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz'}
user                             : {'username': 'callegar', 'name': 'Sergio Callegari'}
version                          : {'version': '4.0', 'local_modifications': 0, 'revision': 26350}
Network: Compression, packet encoding and encryption
bencode                          : {'': True, 'version': (b'Cython', 4, 0)}
brotli                           : {'': True, 'version': '1.0.7'}
compressors                      : ['zlib', 'lz4', 'brotli']
config                           : {'vsocket.timeout': 5, 'socket.timeout': 20}
digest                           : ['xor', 'hmac+sha512', 'hmac+sha3_512', 'hmac+sha3_384', 'hmac+sha3_256', 'hmac+sha3_224', 'hmac+sha384', 'hmac+sha256', 'hmac+sha224', 'hmac+blake2s', 'hmac+blake2b', 'des']
encoders                         : ['rencode', 'bencode', 'yaml']
gateways                         : {}
interfaces                       : ['lo', 'eth0', 'wlan0', 'lxdbr0', 'vetha9ddb1bd']
lz4                              : {'': True, 'version': '1.1.0+dfsg'}
lzo                              : {'': False}
python-lz4                       : {'': True, 'version': b'1.1.0+dfsg'}
rencode                          : {'': True, 'version': ('Cython', 1, 0, 5)}
salt-digest                      : ('hmac+sha512', 'hmac+sha3_512', 'hmac+sha3_384', 'hmac+sha3_256', 'hmac+sha3_224', 'hmac+sha384', 'hmac+sha256', 'hmac+sha224', 'hmac+blake2s', 'hmac+blake2b')
system                           : {'core': {'netdev_max_backlog': 1000, 'optmem_max': 20480, 'rmem_default': 212992, 'rmem_max': 212992, 'wmem_default': 212992, 'wmem_max': 212992, 'max_skb_frags': 17, 'busy_poll': 0, 'busy_read': 0, 'somaxconn': 128, 'default_qdisc': 'fq_codel'}, 'unix': {'max_dgram_qlen': 512}, 'ipv4': {'ip': {'forward': True, 'forward_use_pmtu': True, 'nonlocal_bind': True, 'dynaddr': True, 'early_demux': True, 'local_port_range': (32768, 60999), 'local_reserved_ports': (), 'default_ttl': 64, 'no_pmtu_disc': 0}, 'tcp': {'abort_on_overflow': True, 'autocorking': True, 'dsack': True, 'ecn_fallback': True, 'fack': True, 'low_latency': True, 'no_metrics_save': True, 'recovery': True, 'retrans_collapse': True, 'timestamps': True, 'workaround_signed_windows': True, 'thin_linear_timeouts': True, 'allowed_congestion_control': 'reno cubic', 'available_congestion_control': 'reno cubic', 'congestion_control': 'cubic', 'early_retrans': '3', 'moderate_rcvbuf': '1', 'rfc1337': '0', 'sack': '1', 'slow_start_after_idle': '1', 'stdurg': '0', 'syncookies': '1', 'tw_reuse': '2', 'window_scaling': '1', 'mem': (186228, 248306, 372456), 'rmem': (4096, 131072, 6291456), 'wmem': (4096, 16384, 4194304), 'adv_win_scale': 1, 'app_win': 31, 'base_mss': 1024, 'ecn': 2, 'fin_timeout': 60, 'frto': 2, 'invalid_ratelimit': 500, 'keepalive_time': 7200, 'keepalive_probes': 9, 'keepalive_intvl': 75, 'max_orphans': 65536, 'max_syn_backlog': 512, 'max_tw_buckets': 65536, 'min_rtt_wlen': 300, 'mtu_probing': 0, 'probe_interval': 600, 'probe_threshold': 8, 'orphan_retries': 0, 'reordering': 3, 'max_reordering': 300, 'retries1': 3, 'retries2': 15, 'synack_retries': 5, 'fastopen': 1, 'syn_retries': 6, 'min_tso_segs': 2, 'pacing_ss_ratio': 200, 'pacing_ca_ratio': 120, 'tso_win_divisor': 3, 'notsent_lowat': 4294967295, 'limit_output_bytes': 1048576, 'challenge_ack_limit': 1000}, 'fwmark_reflect': True, 'icmp': {'echo_ignore_all': True, 'echo_ignore_broadcasts': True, 'ignore_bogus_error_responses': '1', 'errors_use_inbound_ifaddr': '0', 'ratelimit': 1000, 'msgs_per_sec': 1000, 'msgs_burst': 50, 'ratemask': 6168}, 'route': {'min_pmtu': 552, 'mtu_expires': 600, 'min_adv_mss': 256}, 'ipfrag': {'high_thresh': 4194304, 'low_thresh': 3145728, 'time': 30, 'max_dist': 64}, 'igmp': {'max_memberships': 20, 'max_msf': 10, 'qrv': 2}}}
yaml                             : {'': True, 'version': '5.1.2'}
zlib                             : {'': True, 'version': '1.0'}
Encodings: Picture encodings supported
avcodec2                         : (58, 35, 100)
ffmpeg                           : (58, 35, 100)
jpeg                             : 1
pillow                           : 6.1.0
swscale                          : (5, 3, 100)
vpx                              : 1.8.1
webp                             : (0, 6, 1)
x264                             : 155
OpenGL: OpenGL driver and features
avcodec2                         : (58, 35, 100)
ffmpeg                           : (58, 35, 100)
jpeg                             : 1
pillow                           : 6.1.0
swscale                          : (5, 3, 100)
vpx                              : 1.8.1
webp                             : (0, 6, 1)
x264                             : 155

Thu, 14 May 2020 22:19:27 GMT - callegar:

Just noticed that the xpra bug-report tool spills out too much information to be pasted on a public forum, like here. User details like real name, public host name + user account. Is there any way to permanently delete a ticket?

Fri, 15 May 2020 02:52:12 GMT - Antoine Martin: owner, description changed

I've removed the keyboard mapping and audio information since this is just a waste of space for an Xdummy related problem.

xpra start :101
DISPLAY=:101 xterm &

Always use: xpra start :101 --start=xterm instead.

Unless I can reproduce this bug on my test system, it is fair to assume that this problem is specific to your system.

at this point, the xterm is briefly shown but xdummy crashes right after.

Does the server crash? Or the client?

If the server, please run it with -d all and attach the server log. If the client, please post the client output (also running it with -d all).

Fri, 15 May 2020 22:50:18 GMT - callegar:

Seems to be Xdummy to crash. This is the Xorg log in the /run/user/.../xpra directory.

[ 92979.720] (EE)
[ 92979.720] (EE) Backtrace:
[ 92979.720] (EE) 0: /usr/lib/xorg/Xorg-for-Xpra-S32265 (OsLookupColor+0x13c) [0x55e4bda04acc]
[ 92979.721] (EE) 1: /lib/x86_64-linux-gnu/libpthread.so.0 (funlockfile+0x60) [0x7fadd176059f]
[ 92979.721] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (gsignal+0xcb) [0x7fadd159e3eb]
[ 92979.721] (EE) 3: /lib/x86_64-linux-gnu/libc.so.6 (abort+0x12b) [0x7fadd157d899]
[ 92979.721] (EE) unw_get_proc_name failed: no unwind info found [-10]
[ 92979.721] (EE) 4: /lib/x86_64-linux-gnu/libc.so.6 (?+0x0) [0x7fadd157d75a]
[ 92979.721] (EE) 5: /lib/x86_64-linux-gnu/libc.so.6 (__assert_fail+0x46) [0x7fadd158f006]
[ 92979.721] (EE) 6: /usr/lib/xorg/Xorg-for-Xpra-S32265 (DRIMoveBuffersHelper+0xc15) [0x55e4bd9cfaa5]
[ 92979.721] (EE) 7: /usr/lib/xorg/Xorg-for-Xpra-S32265 (DRI2Authenticate+0xa2) [0x55e4bd9d10f2]
[ 92979.721] (EE) 8: /usr/lib/xorg/Xorg-for-Xpra-S32265 (DRI2GetParam+0x944) [0x55e4bd9d24b4]
[ 92979.722] (EE) 9: /usr/lib/xorg/Xorg-for-Xpra-S32265 (SendErrorToClient+0x354) [0x55e4bd8a3f44]
[ 92979.722] (EE) 10: /usr/lib/xorg/Xorg-for-Xpra-S32265 (InitFonts+0x3b4) [0x55e4bd8a7fd4]
[ 92979.722] (EE) 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf3) [0x7fadd157f1e3]
[ 92979.722] (EE) 12: /usr/lib/xorg/Xorg-for-Xpra-S32265 (_start+0x2e) [0x55e4bd891a1e]
[ 92979.722] (EE)
[ 92979.722] (EE)
Fatal server error:
[ 92979.722] (EE) Caught signal 6 (Aborted). Server aborting
[ 92979.722] (EE)
[ 92979.722] (EE)
Please consult the The X.Org Foundation support
         at http://wiki.x.org

I'll try to get further info using the flags you suggested. In the meantime, thanks for removing the keyboard mapping and audio information. Please, can the hostname in host: entry be also removed from the system Xpra version, platform and host information section above?

Sat, 16 May 2020 13:05:55 GMT - Antoine Martin: description changed

Please, can the hostname in host: entry be also removed..


As per segfault in OsLookupColor: OsLookupColor is just a default function the backtracer seems to pick up when it craps itself out InitFonts is also in your backtrace, so this may be similar: a problem with your font config is triggering a crash.

My guess is that your Xorg installation is borked. You should be able to reproduce this crash without xpra, just by running:

/usr/lib/xorg/Xorg -noreset -novtswitch -nolisten tcp +extension GLX +extension RANDR +extension RENDER -auth $XAUTHORITY -logfile /tmp/test.log -config /etc/xpra/xorg.conf'

If that still crashes, try downgrading the dummy driver - or removing the one provided in the xpra repository.

To workaround this bug, you may want to just switch to Xvfb in /etc/xpra/conf.d/55_server_x11.conf.

Sat, 16 May 2020 14:18:03 GMT - callegar:

Weird, this is an almost new installation of kubuntu 19.10... got the latptop end of Jan. The only non-standard thing is that I have the pristine texlive and the os configured to pick up the fonts in the texlive distro. Main xorg never got a problem either.

I have also tried more recent xorg drivers (from one of the ubuntu ppas) and downgrading xdummy to the distro version... does not change.

Making more tests I have noticed that:

I'll now try to disable the texlive fonts and making your Xorg direct invocation experiment.

Sat, 16 May 2020 14:23:22 GMT - callegar:

Just tested: /usr/lib/xorg/Xorg :101 -noreset -novtswitch -nolisten tcp +extension GLX +extension RANDR +extension RENDER -auth /tmp/xauth-1000-_0 -logfile /tmp/test.log -config /etc/xpra/xorg.conf runs without a hiccup. Obviously I cannot see anything, but I managed launching google-chrome there and running glxinfo which tells me that that DISPLAY is getting GL from llvmpipe.

Sat, 16 May 2020 14:30:19 GMT - callegar:

I was forgetting. Xvfb works fine. ... bug still Xdummy is nicer to have if possible, so I'd be glad to do more tests if you think it is worthy...

Tue, 19 May 2020 08:44:18 GMT - callegar:

Noticed this in the logs:

Xorg-for-Xpra-:101: ../../../../../../include/privates.h:121: dixGetPrivateAddr: Assertion `key->initialized' failed.

Attaching full log

Tue, 19 May 2020 08:45:33 GMT - callegar: attachment set

Xpra server log

Tue, 19 May 2020 08:49:21 GMT - Antoine Martin:

I was forgetting. Xvfb works fine

Then you should probably switch to that.

Xorg-for-Xpra-:101: ../../../../../../include/privates.h:121: dixGetPrivateAddr: Assertion key->initialized' failed.`

Yes, definitely not an xpra bug. Something is messed up.

Tue, 19 May 2020 10:12:44 GMT - callegar:

Opened a bug for xdummy, then. Crossposting here: https://gitlab.freedesktop.org/xorg/driver/xf86-video-dummy/-/issues/3 to help following the issue

Sat, 23 May 2020 19:55:24 GMT - callegar:

Upgraded the ubuntu machine from 19.10 to 20.04 and the issue is gone.

Another lubuntu 19.10 machine (an intel minipc) I have checked did the same, showed the issue and then not anymore after an upgrade to 20.04. So it seems an ubuntu eoan thing.

Can be closed for me, and thanks for the assistance.

Sun, 24 May 2020 02:54:28 GMT - Antoine Martin: status changed; resolution set

Sat, 23 Jan 2021 06:00:07 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2764