We can't necessarily trust that error message No rule to make target `/usr/local/lib/libboost_date_time-mt.dylib', needed by `libledger.3.dylib' because it resulted from an unclean build attempt. The attached log contains an earlier clean build attempt which ends with these errors:
:info:build Undefined symbols for architecture x86_64:
:info:build "boost::filesystem::path::m_normalize()", referenced from:
:info:build ledger::resolve_path(boost::filesystem::path const&) in utils.cc.o
:info:build "boost::re_detail::get_mem_block()", referenced from:
[snip]
