sys-fs/sysfsutils-1.3.0-r1 wasn't able to read values from my 2.6.27-gentoo-r8 kernel, upgrading to 2.1.0 fixed the issue, but nothing in portage noticed that the versions did not match. lm_sensors should check the kernel version and at least warn when libsysfs does not match the running kernel. Reproducible: Always
The only version of sys-fs/sysfsutils available is 2.1.0 so there is no need for forcing that version. Is your portage tree up to date?