I have once reached at 'check phase without X, and failed. Now more inputs (samba, openldap, xorg-server) are added, And I just find that my network is too slow..
So, I hope someone could pick it up :) I'm not familiar with 64bit wine(not needed IMO) and cross-build in Guix, but just set #:system to "i686-linux" seem to work on my x86_64 machine. compositeproto should be propagated by libxcomposite. freetype should be propagated by fontconfig? libxml2 should be propagated by libxslt? cups, openal, osmesa, and gstreamer are not enabled.
