diff --git a/python.make b/python.make
index 50903e7..8d1afa7 100644
--- a/python.make
+++ b/python.make
@@ -99,15 +99,23 @@ $(PYTHON_CACHE_DIR)/virtualenv-$(VIRTUALENV_VERSION).tar.gz:
 	mkdir -p $(PYTHON_CACHE_DIR);
 	cd $(PYTHON_CACHE_DIR); curl -L --remote-name $(VIRTUALENV_URL);
 
-# Eliminate the error message: "make: *** No rule to make target `..'.  Stop."
 # Only when the first goal is python-pip or python-exec.
 # TODO: Maybe we can apply to all python-* goals.
-# XXX: if the goal is an existing file, will show the message: "make: `existing.json' is up to date."
 ifneq (,$(filter $(firstword $(MAKECMDGOALS)),python-pip python-exec python-module))
+# Eliminate the error message: "make: *** No rule to make target `..'.  Stop."
+# XXX: if the goal is an existing file, will show the message: "make: `existing.json' is up to date."
 %::
 	@:;
+
+define PYTHON_DISABLE_TARGETS
+.PHONY: $(1)
+$(1):
+	@:;
+endef
+$(foreach t,$(filter-out python-pip,$(MAKECMDGOALS)),$(eval $(call PYTHON_DISABLE_TARGETS,$(t))))
 endif
 
+
 # XXX: Need to use `make python-exec -- --version` to specify options to python programs.
 .PHONY: python-exec
 python-exec: COMMAND := $(filter-out python-exec,$(MAKECMDGOALS))
diff --git a/tests/GNUmakefile b/tests/GNUmakefile
index fabb7ec..c8f4cef 100644
--- a/tests/GNUmakefile
+++ b/tests/GNUmakefile
@@ -16,8 +16,9 @@ distclean: clean
 	rm -rf shunit2-$(SHUNIT2_VERSION).zip;
 
 .PHONY: test
+test: export PYTHON_CACHE_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST)))).cache
 test: prepare-shunit2
-	./runtime_test.sh
+	LIB_DIR=shunit2/lib shunit2/test_runner -s /bin/bash
 
 # ---------------------------------------------------------------------------
 
@@ -27,14 +28,8 @@ SHUNIT2_URL     = https://github.com/kward/shunit2/archive/v$(SHUNIT2_VERSION).z
 .PHONY: prepare-shunit2
 prepare-shunit2: shunit2
 
-shunit2: shunit2-$(SHUNIT2_VERSION)
-	ln -sf shunit2-$(SHUNIT2_VERSION) shunit2;
-
-shunit2-$(SHUNIT2_VERSION): shunit2-$(SHUNIT2_VERSION).zip
+shunit2:
+	wget --content-disposition $(SHUNIT2_URL);  # will download shunit2-$(SHUNIT2_VERSION).zip
 	unzip -q shunit2-$(SHUNIT2_VERSION).zip;
-
-shunit2-$(SHUNIT2_VERSION).zip:
-	wget --content-disposition $(SHUNIT2_URL)  # will download shunit2-$(SHUNIT2_VERSION).zip
-#	tar -xf $(TOP_3RDPARTY_DIR)/shunit2-2.1.5.tgz;
-#	( cd shunit2-*; patch -p0 < $(TOP_3RDPARTY_DIR)/shunit2-xml.patch; )
+	ln -sf shunit2-$(SHUNIT2_VERSION) shunit2;
 
diff --git a/tests/pip_test.sh b/tests/pip_test.sh
new file mode 100755
index 0000000..2f1d563
--- /dev/null
+++ b/tests/pip_test.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+test_pip_search_ralc_not_target() {
+	workdir=`mktemp -d tmp.${FUNCNAME[0]}.XXX`;  # $workdir will be available globally
+	cp ../python.make $workdir/;
+	echo "include python.make" > $workdir/GNUmakefile;
+	pushd $workdir;
+
+	make python-runtime
+	make python-pip search ralc
+	assertTrue "ralc file shall not be created" "[ ! -f ralc ]";
+
+	popd
+	rm -rf $workdir;
+}
+
+test_pip_search_ralc_is_target() {
+	workdir=`mktemp -d tmp.${FUNCNAME[0]}.XXX`;  # $workdir will be available globally
+	cp ../python.make $workdir/;
+	echo "
+ralc:
+	touch \$@
+
+include python.make
+" > $workdir/GNUmakefile;
+	pushd $workdir;
+
+	make python-runtime
+	make python-pip search ralc
+	assertTrue "ralc file shall not be created" "[ ! -f ralc ]";
+
+	popd
+	rm -rf $workdir;
+}
+
+test_pip_search_ralc_is_file() {
+	workdir=`mktemp -d tmp.${FUNCNAME[0]}.XXX`;  # $workdir will be available globally
+	cp ../python.make $workdir/;
+	echo "include python.make" > $workdir/GNUmakefile;
+	touch $workdir/ralc
+	pushd $workdir;
+
+	make python-runtime
+	make python-pip search ralc
+	assertTrue "ralc file shall not be removed" "[ -f ralc ]";
+
+	popd
+	rm -rf $workdir;
+}
+
+# Load shUnit2.
+. ./shunit2/shunit2
+