I didn't have jansson installed when I built reaperprime, so I downloaded the newest one (v2.4). But when I used that one, reaperprime ran into a compilation error. Maybe the API changed?
Here's the patch. It compiles and runs. Fingers crossed that it still works -- I have NO idea

--- App.cpp.orig 2013-09-08 09:53:17.022105436 -0500
+++ App.cpp 2013-09-08 09:53:17.126105439 -0500
@@ -98,7 +98,7 @@
blktemplate_t* tmpl = app.templates[w.templateid];
uint NONCE = EndianSwap(*(uint*)&w.data[76]);
- json_t* readyblock = blkmk_submit_jansson(tmpl, &w.data[0], w.dataid, NONCE, &w.auxdata[0], w.auxdata.size());
+ json_t* readyblock = blkmk_submit_jansson(tmpl, &w.data[0], w.dataid, NONCE);
char *s = json_dumps(readyblock, JSON_INDENT(2));
str = s;
free(s);