--- doc/Makefile.in.orig	2021-12-01 13:11:01.000000000 -0500
+++ doc/Makefile.in	2021-12-01 13:11:15.000000000 -0500
@@ -534,7 +534,7 @@
 noinst_DATA = $(figures) $(rst_files) $(static_files)
 EXTRA_DIST = $(man_MANS) $(noinst_DATA) gsl-design.texi gsl-ref.info conf.py
 SPHINX_OPTS = 
-SPHINX_BUILD = sphinx-build
+SPHINX_BUILD = __MACPORTS_SPHINX_BUILD__
 SPHINX_SOURCEDIR = .
 SPHINX_BUILDDIR = _build