I usually build windows binaries under mingw64 and deploy these on PostgreSQL Windows EDB distributions.
This works just fine for the pg_sphere 1.5.2 (master) branch for the 14-16 I have tried building so far, except for PostgreSQL 17.

Note I have already built binaries for PostGIS, MobilityDb, pgRouting, h3 and all those build fine and regress fine.

Everything regresses fine on my mingw64 PG 17 install, but when I try to do

CREATE EXTENSION pg_sphere;

on my PostgreSQL Windows EDB 17, pg_sphere.dll": The specified procedure could not be found.

I've narrowed the issue down to output.c, but I can't figure out what is wrong with that file. Perhaps it's using some function that used to be there for windows for PG < 17 perhaps.

How I know it's the culprit is if I change the Makefile to below - leaving out output.o

OBJS = src/sscan.o src/sparse.o src/sbuffer.o src/vector3d.o src/point.o \
			 src/euler.o src/circle.o src/circle_sel.o src/line.o src/ellipse.o src/polygon.o \
			src/path.o src/box.o src/gq_cache.o src/gist.o src/gist_support.o src/key.o src/gnomo.o src/epochprop.o src/brin.o

I at least get a library that tries to load, but fails on not being able to find the functions in output.c
Any thoughts on what this issue could be?