notmuch 0.19 build fails on OS X 10.6 with gcc 4.2.1 with undefined symbols

[Ryan Schmidt <notmuch@ryandesign.com>]

Hello,

I'm a developer with the MacPorts project and I discovered that notmuch 0.19 does not build on Mac OS X 10.6 with its gcc 4.2.1 compiler. The errors are:


/usr/bin/g++-4.2 command-line-arguments.o debugger.o gmime-filter-reply.o hooks.o notmuch.o notmuch-compact.o notmuch-config.o notmuch-count.o notmuch-dump.o notmuch-insert.o notmuch-new.o notmuch-reply.o notmuch-restore.o notmuch-search.o notmuch-setup.o notmuch-show.o notmuch-tag.o notmuch-time.o sprinter-json.o sprinter-sexp.o sprinter-text.o query-string.o mime-node.o crypto.o tag-util.o -L/opt/local/lib -Wl,-headerpad_max_install_names -arch x86_64 -Lutil -lutil -Llib -lnotmuch   -L/opt/local/lib -lgmime-2.6 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lintl  -L/opt/local/lib -Wl,-rpath,/opt/local/lib -ltalloc  -L/opt/local/lib -lz  -L/opt/local/lib -lgmime-2.6 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lintl  -L/opt/local/lib -Wl,-rpath,/opt/local/lib -ltalloc  -L/opt/local/lib -lz  -L/opt/local/lib -lxapian -o notmuch-shared
Undefined symbols:
  "_hex_decode_inplace", referenced from:
      _parse_tag_line in tag-util.o
  "_gz_error_string", referenced from:
      _notmuch_restore_command in notmuch-restore.o
      _notmuch_restore_command in notmuch-restore.o
  "_gz_getline", referenced from:
      _notmuch_restore_command in notmuch-restore.o
      _notmuch_restore_command in notmuch-restore.o
  "_hex_encode", referenced from:
      _notmuch_database_dump in notmuch-dump.o
  "_talloc_strndup_named_const", referenced from:
      _notmuch_restore_command in notmuch-restore.o
      _notmuch_restore_command in notmuch-restore.o
ld: symbol(s) not found


Here is a full log, from the MacPorts project's automated build server:

https://build.macports.org/builders/buildports-snowleopard-x86_64/builds/35355/steps/compile/logs/stdio


I have tried to understand what's happening here but I'm not a C programmer and I'm not succeeding. The build succeeds on OS X 10.7, 10.8, 10.9 and 10.10 with the clang compiler.

Please let me know if you need additional information!