fakeroot can be built to either use SYSV IPC or TCP for message passing. Cases for which the SYSV IPC version fails or causes problems but for which fakeroot-tcp has been observed to work well include the items listed below. * Multithreaded applications (using pthread) * Running under realtime-preempt kernel Portability Notes On OS X, only binaries that do NOT rely on Mach-based [e]uid/[e]gid/mode APIs will correctly use fakeroot altered ownership/permissions. See README_MACOSX.txt for further information.