* regressions/Makefile.am (TESTS_ENVIRONMENT): Always set
MALLOC_PERTURB_ to a random value in 1..255.
 FAILING_TESTS = \
        test-qemudie-launchfail.sh
 
+random_val := $(shell awk 'BEGIN{srand(); print 1+int(255*rand())}' < /dev/null)
+
 TESTS_ENVIRONMENT = \
+       MALLOC_PERTURB_=$(random_val) \
        LD_LIBRARY_PATH=$(top_builddir)/src/.libs \
        LIBGUESTFS_PATH=$(top_builddir)/appliance \
        NOEXEC_CHECK="$(top_builddir)/src/.libs/libguestfs.so $(top_builddir)/daemon/guestfsd"