use autocrap test facility to get the standard TESTS_ENVIRONMENT

configure.ac

@@ -40,6 +40,9 @@ fi
 AC_HEADER_STDC
 AC_CHECK_HEADERS([sys/stdlib.h])
 
+VMOD_TESTS="$(cd $srcdir/src && echo tests/*.vtc)"
+AC_SUBST(VMOD_TESTS)
+
 # backwards compat with older pkg-config
 # - pull in AC_DEFUN from pkg.m4
 m4_ifndef([PKG_CHECK_VAR], [

src/Makefile.am

 AM_CPPFLAGS = @VMOD_INCLUDES@ -Wall -Werror
 
+TESTS_ENVIRONMENT = PATH=$(LIBVARNISHAPI_BINDIR):$(LIBVARNISHAPI_SBINDIR):$$PATH
+
 vmoddir = @VMOD_DIR@
 vmod_LTLIBRARIES = libvmod_vtstor.la
 
@@ -24,13 +26,12 @@ vmod_vtstor.lo vmod_vtstor.man.rst: vcc
 vcc: @VMODTOOL@ $(top_srcdir)/src/vmod_vtstor.vcc
 	@PYTHON@ @VMODTOOL@ $(top_srcdir)/src/vmod_vtstor.vcc
 
-VMOD_TESTS = $(top_srcdir)/src/tests/*.vtc
-.PHONY: $(VMOD_TESTS) vcc
-
-$(top_srcdir)/src/tests/*.vtc: libvmod_vtstor.la
-	@VARNISHTEST@ -Dvarnishd=@VARNISHD@ -Dvmod_topbuild=$(abs_top_builddir) $@
+VTC_LOG_COMPILER = $(VARNISHTEST) -v \
+	-Dvmod_topbuild=$(abs_top_builddir)
+TEST_EXTENSIONS = .vtc
+TESTS = @VMOD_TESTS@
 
-check: $(VMOD_TESTS)
+@VMOD_TESTS@: vcc
 
 EXTRA_DIST = \
 	vmod_vtstor.vcc \