The ebuild fails with this message:
* Checking for suitable kernel configuration options...
* CONFIG_SENSORS_HDAPS:\t is not set when it should be.
* Please check to make sure these options are set correctly.
* Failure to do so may cause unexpected problems.
* Once you have satisfied these options, please try merging
* this package again.
I actually have the hdaps module - it is provided by the app-laptop/tp_smapi ebuild (when built with the "hdaps" USE flag).
A working solution for this is too complex as the ebuild being merged does not imply existance of the hdaps module if not specified in the kernel.
When tp_smapi is merged into the kernel (hopefully) then this problem should go away, until then you'll have to enable the module in the kernel. Don't panic though, as if tp_smapi provides the hdaps module then we'll use that by default.
thanks, i'll try that