I see. Yes, I hadn't thought Cygwin would be causing problems. Thanks to this, and some help from you on Stack Overflow, I've at least managed to compile libboost_serialization.a against ndk r8d. Unfortunately, when I go to build my app, I am now getting: ./boost/archive/impl/xml_iarchive_impl.ipp:71:error: undefined reference to 'mbtowc' (four instances of that in that file) ./boost/archive/iterators/mb_from_wchar.hpp:91 error: undefined reference to 'wctomb' (two instances of that in that file) I see three possibilities: 1. NDK r8 doesn't support these methods. I've heard / seen this many places, and the solution has been 'use CrystaX r7'. Following that train of thought back in January lead me to the problems at the start of this thread. So, maybe I just need to write these functions myself. I'm not very comfortable writing low-level C code to do so, but I could probably figure it out. I've come across some documentation of what they're supposed to do. 2. NDK r8 does support these functions, but there are some flags I need to set before the NDK will know to include them. I sort of see some macros in those stl files that might be doing something like this, but I could use some help in knowing how to employ them in my code or makefiles. 3. Something else entirely that I haven't considered. It seems odd that I was able to build libboost_serialization.a at all against the NDK when it requires these functions... but maybe it only compiled against archive headers, and didn't require the mbtowc and its complement be defined anywhere? In any case, I am once again stumped by this issue. -- View this message in context: http://boost.2283326.n4.nabble.com/Android-segfault-while-writing-to-archive... Sent from the Boost - Users mailing list archive at Nabble.com.