See also
my answer on GH 
.
As knc1 said, I'd strongly opt for a custom TC, since you're likely to eat dirt on myriad other weird and interesting ABI mismatches otherwise. There's already a whole section dedicated to that in the KOReader Makefile, as well as in my buildscript

.
As I mentioned on GH, I'm a ct-ng fan, and as knc1 mentioned, my configs are up; but BR probably does the job perfectly well too, if you can get it to use the required fairly ancient glibc version (not as well versed in the panel of choices available on BR).