Packages building with opencl will fail because of sandbox in combination with cuda accelerated opencl.
Created attachment 429320 [details]
For me this looks like a bug in the sci-chemistry/chemical-mime-data ebuild, which can be fixed by adding RESTRICT="userpriv" and granting write access to nvidia-uvm etc. as for example done within this  ebuild.
Created attachment 584974 [details, diff]
Fix the emerge by allowing access to the relevant GPU related files as suggested in Marius Brehler's comment.
(In reply to Marius Brehler from comment #2)
> For me this looks like a bug in the sci-chemistry/chemical-mime-data ebuild,
> which can be fixed by adding RESTRICT="userpriv" and granting write access
> to nvidia-uvm etc. as for example done within this  ebuild.
Using a similar mechanism works. But I am not sure what the best approach is.
My attached patch is checking for the opencl use flags, but this is misleading at best, as the question is if /usr/bin/convert, i.e. media-gfx/imagemagick, is actually emerged with opencl, and inserting an IUSE="opencl" is just recognising global USE flags.
Also, I don't know how vendor specific this is.
Nonetheless, I could emerge again. So thanks for the tip.