+PYTHON_VERSION=$(shell $(PYTHON_INTERP) -c 'import sys; print(sys.version_info.major)')
+PIP_VERSION=19.1.1
+PIP_TOOLS_VERSION=3.8.0 # Keep in sync with requirements.txt
+PYTHON_DEPENDS=requirements-$(PYTHON_VERSION).txt
+SCAPY_SOURCE=$(shell find $(VENV_PATH)/lib/$(PYTHON_INTERP) -name site-packages)
+BUILD_COV_DIR=$(TEST_DIR)/coverage
+
+PIP_TOOLS_INSTALL_DONE=$(TEST_RUN_DIR)/pip-tools-install-$(PYTHON_VERSION).done
+PIP_INSTALL_DONE=$(TEST_RUN_DIR)/pip-install-$(PYTHON_VERSION).done
+PIP_PATCH_DONE=$(TEST_RUN_DIR)/pip-patch-$(PYTHON_VERSION).done
+PAPI_INSTALL_DONE=$(TEST_RUN_DIR)/papi-install-$(PYTHON_VERSION).done
+
+PAPI_INSTALL_FLAGS=$(PIP_INSTALL_DONE) $(PIP_PATCH_DONE) $(PAPI_INSTALL_DONE)
+
+$(PIP_TOOLS_INSTALL_DONE):
+ @rm -rf $(VENV_PATH)
+ @mkdir -p $(TEST_RUN_DIR)
+ @virtualenv $(VENV_PATH) -p $(PYTHON_INTERP)
+ # pip version pinning
+ @bash -c "source $(VENV_PATH)/bin/activate && \
+ $(PYTHON_INTERP) -m pip install pip===$(PIP_VERSION)"
+ @bash -c "source $(VENV_PATH)/bin/activate && \
+ $(PYTHON_INTERP) -m pip install pip-tools===$(PIP_TOOLS_VERSION)"
+ @touch $@
+
+$(PYTHON_DEPENDS): $(PIP_TOOLS_INSTALL_DONE) requirements.txt
+ @bash -c "source $(VENV_PATH)/bin/activate && \
+ CUSTOM_COMPILE_COMMAND='make test-refresh-deps (or update requirements.txt)' \
+ $(PYTHON_INTERP) -m piptools compile -q --generate-hashes requirements.txt --output-file $@"