From 2bfb85e52ebce4aa6aa24618972cafacec21840a Mon Sep 17 00:00:00 2001
From: Anthony Sottile <asottile@umich.edu>
Date: Sat, 12 Apr 2014 23:25:49 -0700
Subject: [PATCH] Rebuild virtualenv on requirements change.

---
 .gitignore |  1 +
 Makefile   | 18 ++++++++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/.gitignore b/.gitignore
index 3c8c00ad..a63d861a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@
 .project
 .pydevproject
 .tox
+.venv.touch
 /venv*
 coverage-html
 dist
diff --git a/Makefile b/Makefile
index 5eff62ea..7399eb3a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,17 +1,27 @@
+
+REBUILD_FLAG =
+
 .PHONY: all
 all: venv test
 
 .PHONY: venv
-venv:
-	tox -e venv
+venv: .venv.touch
+	tox -e venv $(REBUILD_FLAG)
 
 .PHONY: tests test
 tests: test
-test:
-	tox
+test: .venv.touch
+	tox $(REBUILD_FLAG)
+
+
+.venv.touch: setup.py requirements.txt requirements_dev.txt
+	$(eval REBUILD_FLAG := --recreate)
+	touch .venv.touch
+
 
 .PHONY: clean
 clean:
 	find . -iname '*.pyc' | xargs rm -f
 	rm -rf .tox
 	rm -rf ./venv-*
+	rm -f .venv.touch