xmalloc was a debug malloc implementation, but the x{malloc,calloc,free} functions default to calling the jemalloc(3) equivalents.
Instead of relying on this malloc shim, I think we can devise better ways to debug malloc issues that aren't misleading upon initial inspection. I've gone ahead and replaced all of the calls with their jemalloc(3) equivalents so that it's obvious that they follow its behavior.