The newly-released torsocks v2.1.0 does not build in RHEL/CentOS v5.11 (all updates applied.) This is the first error: In file included from ref.h:23, from connection.h:28, from defaults.h:21, from log.c:27: compat.h:133:25: error: sys/eventfd.h: No such file or directory make[2]: *** [log.lo] Error 1 This is due to the fact that eventfd.h really does not exist on this system. If I change the include from sys/eventfd.h to sys/syscall.h the compile finishes without error, but then the link fails: ../../src/lib/.libs/libtorsocks.so: undefined reference to `eventfd' ../../src/lib/.libs/libtorsocks.so: undefined reference to `inotify_init1' ../../src/lib/.libs/libtorsocks.so: undefined reference to `epoll_create1' ../../src/lib/.libs/libtorsocks.so: undefined reference to `epoll_pwait' collect2: ld returned 1 exit status No problems seen when building on a CentOS6 system, just on CentOS5. The prior v2.0.0 does build on CentOS5 with the help of some function attribute trickery (prepending ATTR_HIDDEN to several function and data definitions). **Trac**: **Username**: tmpname0901