El iMac se cierra aleatoriamente (High Sierra y Mojave)

TLDR: En mi caso, SwitchResX parece ser el culpable. Todavía no he buscado una solución.

Acabo de experimentar el mismo cierre de sesión, con registros similares:

Jun  2 15:21:55 Trema syslogd[48]: ASL Sender Statistics
Jun  2 15:24:07 Trema com.apple.xpc.launchd[1] (com.apple.quicklook[8406]): Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): com.apple.quicklook
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.WindowServer[205]): Service exited due to SIGABRT
Jun  2 15:24:35 Trema VDCAssistant[203]: BUG in libdispatch client: mach_recv, monitored resource vanished before the source cancel handler was invoked { 0x7fb4e8c0b840[source], ident: 6191 / 0x182f, handler: 0x107f6fa6c }
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.ViewBridgeAuxiliary[8527]): Service exited with abnormal code: 2
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.ViewBridgeAuxiliary): Service only ran for 0 seconds. Pushing respawn out by 10 seconds.
Jun  2 15:24:35 Trema sessionlogoutd[8526]: DEAD_PROCESS: 102 console
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.UserEventAgent-Aqua[606]): Service exited due to SIGKILL | sent by UserEventAgent[606]
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.BE261D11-9005-48E6-9B64-31D068C12BB4[4827]): Service exited with abnormal code: 1
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.WebKit.WebContent.5B14717F-EC42-44AC-BE76-917F52D439A9[4829]): Service exited with abnormal code: 1
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.adobe.GC.AGM[1366]): Service exited with abnormal code: 15
Jun  2 15:24:35 Trema com.apple.xpc.launchd[1] (com.apple.Dock.agent[662]): Service exited with abnormal code: 1

Como sugiere @Ruskes, he ejecutado el comando sudo log show --start "2020-06-02 15:24:00" --info --debug --signpost y vi estas interesantes líneas:

2020-06-02 15:24:34.477103+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Unsupported Extended capabilities type: 0x100
2020-06-02 15:24:34.477135+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.477171+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.477203+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.477238+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.477272+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.477300+0200 0x4a3      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Currently unsupported feature requested
2020-06-02 15:24:34.480826+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005000, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 7680 stored width = 1920. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480844+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005001, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 4096 stored width = 1024. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480858+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005002, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 4096 stored width = 1024. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480872+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005003, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 3200 stored width = 800. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480886+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005004, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 3200 stored width = 800. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480900+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005005, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 2560 stored width = 640. Forcing minRowBytes (possibly still wrong).
2020-06-02 15:24:34.480913+0200 0x4a3      Error       0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [ERROR] - Driver bug - rowBytes too small. Display 0x1c81a9e2, ioModeID 0x80005006, ioModeDepth 0x0, bytePerRow = 32, width = 1, bitsPerPixel = 32, minRowBytes = 2560 stored width = 640. Forcing minRowBytes (possibly still wrong).

[...]

2020-06-02 15:24:35.254853+0200 0x4a3      Default     0x0                  205    7    WindowServer: (CoreDisplay) [com.apple.CoreDisplay:default] [WARN] - description_for_mode_number: Illegal mode number -1 for display 003f003f
2020-06-02 15:24:35.255600+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:Standard] -[LoginApp windowServerExited] | enter
2020-06-02 15:24:35.255630+0200 0x4c6      Default     0x0                  0      0    kernel: (AppleIntelFramebufferAzul) Transitioning wsaa from 1->0
2020-06-02 15:24:35.255684+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:LWError] -[LoginApp windowServerExited] | ERROR | Window Server exited, closing down the session immediately
2020-06-02 15:24:35.255886+0200 0xd90d     Default     0x0                  664    0    SystemUIServer: (HIToolbox) HIToolbox: received notification of WindowServer event port death.
2020-06-02 15:24:35.255930+0200 0xd90d     Default     0x0                  664    0    SystemUIServer: (HIToolbox) port matched the WindowServer port created in BindCGSToRunLoop
2020-06-02 15:24:35.256039+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:Standard] -[SessionLogoutManager startDirectLogout:reason:] | Enter, logoutType: Logout,  directLogoutReason:WindowServerExited
2020-06-02 15:24:35.256041+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:Standard] -[SessionLogoutManager startDirectLogout:reason:] | Window server exit, calling doDirectLogoutFinalItemsBeforeSessionLogoutd
2020-06-02 15:24:35.256050+0200 0xd906     Default     0x0                  661    0    talagent: (HIToolbox) HIToolbox: received notification of WindowServer event port death.
2020-06-02 15:24:35.256096+0200 0xd906     Default     0x0                  661    0    talagent: (HIToolbox) port matched the WindowServer port created in BindCGSToRunLoop
2020-06-02 15:24:35.256113+0200 0xd7fe     Default     0x0                  624    0    Google Chrome: (HIToolbox) HIToolbox: received notification of WindowServer event port death.
2020-06-02 15:24:35.256124+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:Standard] -[SessionLogoutManager doDirectLogoutFinalItemsBeforeSessionLogoutd] | enter
2020-06-02 15:24:35.256154+0200 0xd7fe     Default     0x0                  624    0    Google Chrome: (HIToolbox) port matched the WindowServer port created in BindCGSToRunLoop
2020-06-02 15:24:35.256200+0200 0x65e31    Default     0x0                  8184   0    ProtonMail Bridge: (HIToolbox) HIToolbox: received notification of WindowServer event port death.
2020-06-02 15:24:35.256214+0200 0x269      Default     0x0                  102    5    loginwindow: [com.apple.loginwindow.logging:Standard] -[SessionLogoutManager doCommonFinalItems] | enter
2020-06-02 15:24:35.256216+0200 0x269      Signpost    0x0                  102    0    [spid excl, process, event] loginwindow: [com.apple.loginwindow.logging:performance_instrumentation] Dock_Dies

Tengo dos pantallas externas, y uso SwitchResX para ajustar la pantalla de una de ellas para forzar una densidad de 1440p similar a la de retina sobre 1080p (conectada por HDMI), y otra pantalla (a través del adaptador VGA-MiniDisplay) está simplemente a 1080p.

Los primeros errores en los registros detallados parecen estar relacionados con las resoluciones personalizadas de SwitchResX (nótese los 1920, 1024, 800 ), ya que registra resoluciones potencialmente no soportadas.

Por ahora, deduzco que esto desencadena el fallo de WindowServer, y luego los cierres de sesión, pero aún no he encontrado una solución.

Se agradece cualquier aportación.