+# urcu - check that URCU lib is at least version 0.5.4
+AC_CHECK_LIB([urcu-bp], [rcu_bp_before_fork], [], [AC_MSG_ERROR([liburcu 0.5.4 or newer is needed, please update your version or use [LDFLAGS]=-Ldir to specify the right location.])])
+
+# urcu - check that URCU lib is at least version 0.5
+AC_CHECK_DECL([cds_list_add(0, 0)], [], [AC_MSG_ERROR([liburcu 0.5 or newer is needed, please update your version or use [LDFLAGS]=-Ldir to specify the right location.])], [[#include <urcu/list.h>]])
+
+
+
+# Check for various supplementary host information (beyond the
+# triplet) which might affect the library format choices. E.g., we
+# can be building with `i686-unknown-linux-gnu-gcc -m64'