--- /dev/null
+#include <sys/types.h>
+
+// Mock system functions for testing.
+
+namespace bp_sys {
+
+inline int pipe2(int pipefd[2], int flags)
+{
+ abort();
+ return 0;
+}
+
+inline int fcntl(int fd, int cmd, ...)
+{
+ // This is used for setting the CLOEXEC flag, we can just return 0:
+ return 0;
+}
+
+inline int close(int fd)
+{
+ abort();
+ return 0;
+}
+
+inline int kill(pid_t pid, int sig)
+{
+ abort();
+ return 0;
+}
+
+}