As you found out yourself, the art backend doesn't work with 8 bit, but xlib and cairo will. I will close this bug as there is a suitable workaround.

Perhaps I will look into this a bit later, as I noticed I get the same problem when running a GNUstep application with my monitor in the fallback mode. We really need a better error message for the user.

Same results.

Running GNUstep into a VNC X server (Xvnc).
When using default 16 bit depth, the following error arises:

| gnustep-back(art): Unrecognized color masks:
| 0000003f:000007c0:0000f800 16
| Gorm[29951] Please report this along with details on your pixel
| format (ie. the four numbers above) to
| bug-gnustep@gnu.org.Better: implement it and send a patch.)

the same happens if I use -depth 8 or -depth 15. In these cases, this appears before:

| 2005-06-20 18:40:48.000 Gorm[30122] WARNING - XGServer is
| unable to use the fast algorithm for writing to an 8-bit
| display on this host - the most likely reason being the
| StandardColormap RGB_BEST_MAP has not been installed.

If the Xvnc server was started with -depth 24, everything works.

Using GNUstep CVS from today 2005-06-20.

Sorry, but no idea how to send a patch :)

Paolo <oopla@users.sf.net> reports:

I'm accessing a Sarge sys via a vnc session at 8bit, and all I got is:

2005-02-26 06:59:40.000 GWorkspace[31699] NOTE: Only one display per host fully supported.
2005-02-26 06:59:40.000 GWorkspace[31699] WARNING - XGServer is unable to use the fast algorithm for writing to an 8-bit display on this host - the most likely reason being the StandardColormap RGB_BEST_MAP has not been installed.
2005-02-26 06:59:40.000 GWorkspace[31699] Unrecognized color masks: 00000007:00000038:000000c0 8
2005-02-26 06:59:40.000 GWorkspace[31699] Please report this along with details on your pixel format (ie. the four numbers above). (Or better yet, implement it and send me a patch.)

-------

Lars Wirzenius <liw@iki.fi> answer:

I tried it with an 8-bit X server running under qemu. The results were pretty much identical: neither GWorkspace nor Mines (the two GNUstep programs I tried) would run. When I configured it to be a 24-bit screen, Mines would run without problems.

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A bug report can be found here:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=296977