commit 9ac1104b075ecea6175e2214b81c6538adbb9e84
Author: Ben Gamari <ben@smart-cactus.org>
Date:   Tue Oct 17 23:53:25 2017 -0400

    Fix it

diff --git a/Makefile.pre.in b/Makefile.pre.in
index e288964..ddc7428 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -1120,27 +1120,27 @@ libinstall:	build_all $(srcdir)/Lib/$(PLATDIR) $(srcdir)/Modules/xxmodule.c
 		$(INSTALL_DATA) $(srcdir)/Modules/xxmodule.c \
 			$(DESTDIR)$(LIBDEST)/distutils/tests ; \
 	fi
-	PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
+	$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -Wi -tt $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST) -f \
 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
 		$(DESTDIR)$(LIBDEST)
-	PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+	$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -Wi -tt -O $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST) -f \
 		-x 'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
 		$(DESTDIR)$(LIBDEST)
-	-PYTHONPATH=$(DESTDIR)$(LIBDEST)  $(RUNSHARED) \
+	-$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -Wi -t $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST)/site-packages -f \
 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+	-$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -Wi -t -O $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST)/site-packages -f \
 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+	-$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/Grammar.txt
-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+	-$(RUNSHARED) \
 		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/PatternGrammar.txt
 
 # Create the PLATDIR source directory, if one wasn't distributed..