Failed to compile on OSX Sierra 10.12

[f34nk]

TidyEx failes to compile on OSX Sierra 10.12 because of missing open_memstream.

[ 13%] Linking C executable tidy_worker
Undefined symbols for architecture x86_64:
  "_open_memstream", referenced from:
      _eterm_vec_join in eterm_vec.c.o
      _eterm_to_string in eterm_vec.c.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [tidy_worker] Error 1
make[1]: *** [CMakeFiles/tidy_worker.dir/all] Error 2
make: *** [all] Error 2

[f34nk]

Same issue with my other package:
f34nk/modest_ex#21