Debugged with http://rsync.samba.org/rsync-debug on the 'other' side [pid 3770] write(1, "\4\0\0\7\377\377\377\377", 8) = 8 [pid 3770] kill(3771, SIGUSR2) = 0 [pid 3770] waitpid(3771, 0xfeef900c, WNOHANG) = 0 [pid 3770] gettimeofday({1101681386, 289321}, NULL) = 0 [pid 3770] select(0, NULL, NULL, NULL, {0, 20000} [pid 3771] --- SIGUSR2 (User defined signal 2) @ 0 (0) --- Process 3771 detached <... select resumed> ) = ? ERESTARTNOHAND (To be restarted) --- SIGCHLD (Child exited) @ 0 (0) --- waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], WNOHANG) = 3771 waitpid(-1, 0xfeef8c84, WNOHANG) = -1 ECHILD (No child processes) sigreturn() = ? (mask now []) gettimeofday({1101681386, 292561}, NULL) = 0 select(0, NULL, NULL, NULL, {0, 17000}) = 0 (Timeout) gettimeofday({1101681386, 309977}, NULL) = 0 waitpid(3771, 0xfeef900c, WNOHANG) = -1 ECHILD (No child processes) rt_sigaction(SIGUSR1, {SIG_IGN}, {0x8052a50, [USR1], SA_RESTORER|SA_RESTART, 0xc6ff48}, 8) = 0 rt_sigaction(SIGUSR2, {SIG_IGN}, {0x8052a80, [USR2], SA_RESTORER|SA_RESTART, 0xc6ff48}, 8) = 0 exit_group(0) = ? and on another run: [pid 3852] write(1, "\31\0\0\tbin/dumpkeys is uptodate\n", 29) = 29 [pid 3852] lstat64("bin/echo", {st_mode=S_IFREG|0755, st_size=16236, ...}) = 0 [pid 3852] select(4, [3], [1], NULL, {60, 0}) = 1 (out [1], left {60, 0}) [pid 3852] write(1, "\25\0\0\tbin/echo is uptodate\n", 25) = -1 EPIPE (Broken pipe) [pid 3852] --- SIGPIPE (Broken pipe) @ 0 (0) --- [pid 3852] write(2, "rsync: writefd_unbuffered failed"..., 98rsync: writefd_unbuffered failed to write 25 bytes: phase "unknown" [generator]: Broken pipe (32) ) = 98 [pid 3852] rt_sigaction(SIGUSR1, {SIG_IGN}, {0x8052a50, [USR1], SA_RESTORER|SA_RESTART, 0x72df48}, 8) = 0 [pid 3852] rt_sigaction(SIGUSR2, {SIG_IGN}, {0x8052a80, [USR2], SA_RESTORER|SA_RESTART, 0x72df48}, 8) = 0 [pid 3852] getpid() = 3852 [pid 3852] kill(3853, SIGUSR1) = 0 [pid 3852] write(2, "rsync error: error in rsync prot"..., 72rsync error: error in rsync protocol data stream (code 12) at io.c(909) ) = 72 [pid 3852] exit_group(12) = ? --- SIGUSR1 (User defined signal 1) @ 0 (0) --- Process 3853 detached rsync: writefd_unbuffered failed to write 69 bytes: phase "unknown" [receiver]: Broken pipe (32) rsync error: error in rsync protocol data stream (code 12) at io.c(909)