Hello, The webkit2gtk package was disabled some time ago on non-Linux platforms. The changelog entry says:
Set the architecture to linux-any, this package depends on the Linux-specific sysinfo() call. It actually uses it only to retrieve the amount of available memory, which GNU Mach has an interface for (vm_statistics, and summing active+inactive+wire+free). Possibly some issues have crept in in the meanwhile, but probably not that many. Any taker? Samuel