Found it:
Change, in backend/access/nbtree/nbtsort.c:
#define TAPETEMP "pg_btsortXXXXXX"
to:
#define TAPETEMP "pg_btsortXXXXXXX"
For some reason, under FreeBSD, it appears that the mktemp() value needs
the extra 'X' to improve/ensure uniqueness
Marc G. Fournier
Systems Administrator @ hub.org
primary: scrappy(at)hub(dot)org secondary: scrappy(at){freebsd|postgresql}.org