NI-VISA final fail

In a previous blog post, I already pointed out that using the NI-VISA library to control lab devices with Linux is becoming more and more painful - especially when you heavily rely on National Instrument's high speed USB-GPIB adapters. But hey, supporting kernels newer than 2.6.24 is luxury anyway, right?
Yesterday I tried to update my "test box" for Linux lab software, just in case I can maybe convince one of my colleagues to work with that strange OS for a change. Then, I realized that for us the NI-VISA package has finally become totally useless:

(meas) pc5xxxx ~ # emerge -uDNav --keep-going world

Performing Global Updates:
(Could take a couple of minutes if you have a lot of binary packages.)
  .='update pass'  *='binary update'  #='/var/db update'  @='/var/db move'
  s='/var/db SLOT move'  %='binary move'  S='binary SLOT move'
  p='update /etc/portage/package.*'
/var/lib/layman/n4g/profiles/updates/4Q-2009..........

These are the packages that would be merged, in order:

Calculating dependencies... done!

!!! All ebuilds that could satisfy ">=sys-fs/udev-151[extras]" have been masked.
!!! One of the following masked packages is required to complete your request:
- sys-fs/udev-9999 (masked by: package.mask, missing keyword)
- sys-fs/udev-168-r2 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-168-r1 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-168 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-167-r1 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-167 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-164-r2 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-164-r1 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-164 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-163 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-162 (masked by: package.mask, ~x86 keyword)
- sys-fs/udev-151-r4 (masked by: package.mask)

(dependency required by "sys-power/upower-0.9.9" [ebuild])
(dependency required by "kde-base/kdelibs-4.6.2-r3" [ebuild])
(dependency required by "kde-base/khelpcenter-4.6.2" [ebuild])
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.

(meas) pc5xxxx ~ #

The age-old kernel requires old udev (<=142 if I remember correctly), which I enforced with a package.mask and now is incompatible with other recent stuff. Ah well... >:| no more VISA on Linux for us.