can't seem to override PREFIX at build time, so patch it
--- minipro-0.5/Makefile	2020-11-04 21:35:31.000000000 -0800
+++ minipro-0.5/Makefile	2022-07-22 11:42:54.866390621 -0700
@@ -9,7 +9,7 @@
 
 # Normally minipro is installed to /usr/local.  If you want to put it
 # somewhere else, define that location here.
-PREFIX ?= /usr/local
+PREFIX ?= /usr
 MANDIR ?= $(PREFIX)/share/man
 
 # Some older releases of MacOS need some extra library flags.