--- ../Makefile.rules.orig	2020-03-23 12:15:43.856232472 +0100
+++ ./Makefile.rules	2020-03-23 14:06:51.875467601 +0100
@@ -483,26 +483,24 @@
 
 LTINSTALL=$(LIBTOOL) --mode=install $(INSTALL)
 
-install:
-	@echo "Error, 'make install' has not yet been implemented"
-	exit 1
+install: install-libgap install-headers install-bin install-gaproot install-pkg
 
 install-bin:
 	@echo "Warning, 'make install-bin' is incomplete"
 	$(INSTALL) -d -m 0755 $(DESTDIR)$(bindir)
-	$(INSTALL) -m 0755 gap $(DESTDIR)$(bindir)/gap.real
-	echo "!/bin/sh\nexec \"$(bindir)/gap.real\" -l \"$(datarootdir)/gap\" \"$@\"" > gap-wrapper.sh
+	$(INSTALL) -m 0755 gap $(PREFIX)/libexec/gap.real
+	echo -e "#!/data/data/com.termux/files/usr/bin/sh\nexec \"$(PREFIX)/libexec/gap.real\" -l \"$(datarootdir)/gap\" "'"$$@"' > gap-wrapper.sh
 	$(INSTALL) -m 0755 gap-wrapper.sh $(DESTDIR)$(bindir)/gap
 	# TODO: make gac installable; this requires adjusting path in it, and
 	# installing the libtool script generated by configure somewhere; and then
 	# putting that path to it into gac)
-	#$(INSTALL) gac $(DESTDIR)$(bindir)
+	$(INSTALL) gac $(DESTDIR)$(bindir)
 
 install-gaproot:
 	@echo "Warning, 'make install-gaproot' is incomplete"
 	$(INSTALL) -d -m 0755 $(DESTDIR)$(datarootdir)/gap
 	# TODO: update paths and FLAGS in sysinfo.gap
-	$(INSTALL) -m 0644 $(srcdir)/sysinfo.gap $(DESTDIR)$(datarootdir)/gap
+	$(INSTALL) -m 0644 sysinfo.gap $(DESTDIR)$(datarootdir)/gap
 	# the following lines should not use `cp -r`, which is not quite portable,
 	# and which also may not deal with file permissions correctly
 	cp -r $(srcdir)/doc $(DESTDIR)$(datarootdir)/gap/  # FIXME: don't use `cp -r`
# @@ -528,6 +526,7 @@
#  	# This could also be used by the PackageManager package (or perhaps we
#  	# should just use PackageManager ourselves, and/or recommend it to
#  	# packagers).
# +	cp -rf $(srcdir)/pkg $(DESTDIR)$(datarootdir)/gap/
#  
#  install-headers:
#  	@echo "Warning, 'make install-headers' is incomplete"
@@ -537,6 +536,7 @@
 	$(INSTALL) -d -m 0755 $(DESTDIR)$(includedir)/gap/hpc
 	$(INSTALL) -m 0644 $(srcdir)/src/hpc/*.h $(DESTDIR)$(includedir)/gap/hpc
 	# TODO: take care of config.h, this is difficult
+	$(INSTALL) -m 0644 gen/config.h $(DESTDIR)$(includedir)/gap
 
 install-libgap: libgap.la
 	@echo "Warning, 'make install-libgap' is incomplete"