games/spring fails to build with CMake 3.12 (which we're about to exp-run). Patches are in https://reviews.freebsd.org/D15878
A commit references this bug:
Date: Tue Jun 19 21:08:34 UTC 2018
New revision: 472823
Pre-emptively fix games/spring before CMake 3.12 arrives.
file(GLOB .. FOLLOW_SYMLINKS ..) was never documented to work; in
3.12-rc1 this has become an error. That in itself is considered
a regression in CMake , but the use is wrong anyway, so patch
it away. The change has been accepted upstream  already.
Not bumping PORTREVISION because no code actually changes,
it just removes a cmake-time no-op.
Reviewed by: tcberner
Differential Revision: https://reviews.freebsd.org/D15878