While the port has LD_LIBMAP to fix the following error for out-of-ports builds bootstrap compiler needs to be rebuilt.
Using compiled compiler at `.build/crystal'
Shared object "libevent-2.1.so.6" not found, required by "crystal"
gmake: *** [Makefile:123: .build/crystal] Error 1
hm, wait — out-of-ports builds, with the bootstrap compiler? Why use the bootstrap compiler out of ports?
Bootstraps will be rebuilt for the next version upgrade, but that's currently on hold due to LLVM bugs..