My /usr/include/libxml2/libxml/tree.h (from libxml2 2.7.3) says xmlDocDumpFormatMemory (xmlDocPtr cur, xmlChar **mem, int *size, int format);so I think this change will cause errors if int != intptr_t (i.e. on 64-bit systems) with that version of libxml2. Older versions (e.g. 2.6.30) seem to use "int *size" too. Where is the intptr_t* coming from? (Edit: Oops, took too long to reply and terato beat me.) Edit again: Oh, this is probably because OS X is using