Bug 1472065 - tigervnc-server-module not working in Fedora 26
tigervnc-server-module not working in Fedora 26
Status: NEW
Product: Fedora
Classification: Fedora
Component: tigervnc (Show other bugs)
Unspecified Linux
unspecified Severity medium
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Assigned To: Jan Grulich
Fedora Extras Quality Assurance
Depends On:
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Reported: 2017-07-17 22:33 EDT by Peter Fales
Modified: 2017-07-17 22:44 EDT (History)
4 users (show)

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Description Peter Fales 2017-07-17 22:33:12 EDT
Description of problem:

I'm using tigervnc-server-module in Fedora 25.  The same configuration does not work in Fedora 26.

Version-Release number of selected component (if applicable):

How reproducible:  Always

Steps to Reproduce:
1.  install tigervnc-server-module ("yum -y install tigervnc-server-module")
2.  Switch to xorg (uncommment "WaylandEnable=false" in /etc/gdm/custom.conf)
3.  Enable vnc module by uncommenting the lines in /etc/X11/xorg.conf.d/10-libvnc.conf
4.  Restart GUI

Actual results:

X server does not start

Expected results:

X server should start with a vnc server listening on port 5900

Additional info:

I was able to get slightly farther by commenting out the line in /etc/X11/xorg.conf.d/10-libvnc.conf that says "DefaultDepth 16".   That allows the X server to start and display the desktop on the console.  However, it still does not work with VNC.   I can connect to the server, and move the mouse, but it shows an out-of-date display that does not match the physical display.

I first tested this on a Lenovo Thinkpad T420 by upgrading it from Fedora 25 to Fedora 26, and was rather frustrated that it (I thought) made the Fedora 26 Desktop unusable.   (The upgrade preserved my F25 configuration, effectively doing steps 1, 2, and 3 above).  I went through some pain and inconvenience to restore F25 from a backup image.

I subsequently was able to reproduce the same scenario when booting from the Fedora 26 live cd.   That's when I found the partial workaround related to "DefaultDepth."   (I mention this last point, because I think it means that someone could test and reproduce this bug using a live cd if that's useful)
Comment 1 Peter Fales 2017-07-17 22:44:13 EDT
Hmm, Maybe not quite a reproducible as I thought...

I tried reproducing it on a VirtualBox VM (which is also running F26 upgraded from F25) and it works there.   In this case, step 2 was not necessary (apparently the VirtualBox hardware does not support Wayland, so it is already falling back to Xorg), but after completing the other steps I'm able to connec t to the VNC server and it shows the correct display.

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