I spent 3-4 days trying to build the webkit-gtk2 port on 10.1 RELEASE. I kept getting a linker error and I tried every solution I could find about it, including trying to change the compiler to use gcc instead of CLANG and making a change in the Makefile etc.
Finally I had a look at the symbols which were generating a linker error and I realised they were all to do with 3d graphics. I was not selecting the WebGL Option in make config and it was still trying to link those routines. So I chose WebGL in make config and the linker didnt fail and I was able to finally build the port. Hope this helps others who are stuck with webkit-gtk2.
It looks like the make file is not filtering the checked options in config and assumes everything is to be linked. It only works if everything is selected in make config.