Configuring --without-bdb
on MacOS leads to a compile error (when BerkeleyDB is not installed). brew --prefix berkeley-db4
always reports the target directory (even if not installed).
This PR prevents BDB_CFLAGS (et al) from being populated when configuring --without-bdb
0ld: warning: directory not found for option '-L/Users/user/Documents/homebrew/Cellar/berkeley-db@4/4.8.30/lib'
1ld: warning: directory not found for option '-L/Users/user/Documents/homebrew/Cellar/berkeley-db@4/4.8.30/lib'
2ld: library not found for -ldb_cxx-4.8
3ld: library not found for -ldb_cxx-4.8