I can normaly mount/umount FTP as file system using following commands:> curlftpfs -o codepage=windows-1250 anonymous:anonymous@192.168.3.13 /home/marek/ftpfs> ls /home/marek/ftpfs/1 2 3> fusermount -u /home/marek/ftpfs> ls /home/marek/ftpfs/>But when I issue curlftpfs with strace then nothing is mounted and the process exits with status 1:> strace -f curlftpfs -o codepage=windows-1250 anonymous:anonymous@192.168.3.13 /home/marek/ftpfs> echo $01> ls /home/marek/ftpfs/>Last lines from strace (full output is here):[pid  9619] mprotect(0x7f08780b2000, 4096, PROT_READ) = 0[pid  9619] mprotect(0x7f08782bd000, 4096, PROT_READ) = 0[pid  9619] munmap(0x7f0878e8d000, 135950) = 0[pid  9619] open(/etc/passwd, O_RDONLY|O_CLOEXEC) = 6[pid  9619] lseek(6, 0, SEEK_CUR)       = 0[pid  9619] fstat(6, {st_mode=S_IFREG|0644, st_size=2290, ...}) = 0[pid  9619] mmap(NULL, 2290, PROT_READ, MAP_SHARED, 6, 0) = 0x7f0878eae000[pid  9619] lseek(6, 2290, SEEK_SET)    = 2290[pid  9619] munmap(0x7f0878eae000, 2290) = 0[pid  9619] close(6)                    = 0[pid  9619] getgid()                    = 1000[pid  9619] getuid()                    = 1000[pid  9619] openat(AT_FDCWD, ., O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 6[pid  9619] getdents(6, /* 2 entries */, 32768) = 48[pid  9619] getdents(6, /* 0 entries */, 32768) = 0[pid  9619] close(6)                    = 0[pid  9619] mount(curlftpfs#ftp://anonymous:anonymous@192.168.3.13/, ., fuse, MS_NOSUID|MS_NODEV, fd=3,rootmode=40000,user_id=1000...) = -1 EPERM (Operation not permitted)[pid  9619] write(2, fusermount: mount failed: Operat..., 50fusermount: mount failed: Operation not permitted) = 50[pid  9619] close(3)                    = 0[pid  9619] exit_group(1)               = ?[pid  9618] <... recvmsg resumed> {msg_name(0)=NULL, msg_iov(1)=[{, 1}], msg_controllen=0, msg_flags=0}, 0) = 0[pid  9618] close(6)                    = 0[pid  9618] wait4(9619,  <unfinished ...>[pid  9619] +++ exited with 1 +++<... wait4 resumed> NULL, 0, NULL)      = 9619--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=9619, si_uid=1000, si_status=1, si_utime=0, si_stime=0} ---sendto(4, QUIT\r\n, 6, MSG_NOSIGNAL, NULL, 0) = 6poll([{fd=4, events=POLLIN|POLLPRI|POLLRDNORM|POLLRDBAND}], 1, 1000) = 1 ([{fd=4, revents=POLLIN|POLLRDNORM}])recvfrom(4, 221 Bye\r\n, 16384, 0, NULL, NULL) = 9close(4)                                = 0close(3)                                = 0exit_group(1)                           = ?+++ exited with 1 +++
exit status of command is different when it is run via strace
mount;ftp;fuse;strace;return status
I am not familiar with this executable, but my guess is that it needs to run with privilege (probably suid root or similar). strace -f cannot run such a process with privilege unless strace itself is run as root and you may need the -u option. 