2 files changed, 10 insertions, 4 deletions
diff --git a/.gitignore b/.gitignore
index 67a94e3..9d5463c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,6 +7,7 @@
 container-runner
 log
 test-root
+Makefile.local
 pidfile
 hosts
 *.touchfile
diff --git a/Makefile b/Makefile
index 0bea659..656a3d2 100644
--- a/Makefile
+++ b/Makefile
@@ -4,14 +4,16 @@
 #
 # Available under the terms of Creative Commons Zero v1.0 Universal.
 
-GUIX := guix
+-include Makefile.local
+
+GUIX ?= guix
 
 # Almost all commands in this Makefilo are run through `guix time-machine` with
 # Guix revision fixed to the one from the commit below. This ensures that the
 # same working environment is always used.
-GUIX_COMMIT := a86979b41a49a8fcdaa887970ba594dbba701226
+GUIX_COMMIT ?= a86979b41a49a8fcdaa887970ba594dbba701226
 
-GUIX_TM = $(GUIX) time-machine --commit=$(GUIX_COMMIT) --
+GUIX_TM ?= $(GUIX) time-machine --commit=$(GUIX_COMMIT) --
 
 GUIX_LOAD_PATHS = $$(                                 \
 	find subrepos/ -mindepth 1 -maxdepth 1        \
@@ -35,7 +37,7 @@ ALL_EGG_INFOS =                    \
 	$(HYDRILLA_INFO)
 
 CONTAINER_PREREQUISITES = container.scm $(ALL_EGG_INFOS) hydrilla-wsgi.py \
-	exim.conf
+	exim.conf Makefile.local
 
 TEST_ROOT_DIR = "/tmp/$$(pwd | sed 's|/|!|g')"'!!test-root/current'
 
@@ -48,6 +50,9 @@ $(HYDRILLA_WEBSITE_INFO):
 $(HYDRILLA_INFO):
 	$(MAKE) -C subrepos/hydrilla dist
 
+Makefile.local:
+	touch $@
+
 container-runner: | $(CONTAINER_PREREQUISITES)
 container-runner.touchfile: $(CONTAINER_PREREQUISITES)