Emerging synaptics under amd64 fails as the makefile sniffs for an installed xorg-server and assumes that all the required xfree86 headers are also present. This assumption fails on my system, so I have patched the makefile to make use of the bundled headers. An ebuild and the patch for the makefile is attached.
Created attachment 190202 [details] the updated ebuild from 0.14.6-r3
Created attachment 190204 [details] this patch adds the bundled headers to the end of the search path of the makefile includes Essentially there is a edge case in the makefile, when xorg-server is installed AND the headers required to build synaptics are not present. The package comes bundled with suitable headers to build against and makes use of them if xorg-server isn't found. The files are added to the search path so in the case where xorg-server is installed and the files are present, the system supplied headers should override the bundled headers.
Please note that xf86-input-synaptics superseeds synaptics. It should build out of the box against X.Org.
synaptics is dead code, please try with xf86-input-synaptics and reopen if this does not fix your issue.
