lspci on my laptop lists:
Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express
Integrated Graphics Controller (rev 03)

I get the same errors when trying to start weston:
...
[] failed to create gbm surface
[] Failed to init output gl state
[] Enabling output "LVDS-1" failed.
[] Error: cannot enable output 'LVDS-1' without heads.

From
https://www.mail-archive.com/wayland-devel@lists.freedesktop.org/msg38763.html
I was able to work around the problem using:

$ weston --use-pixmap