Occasionally I would try launching OctoPkg and nothing would happen. By doing a ktrace I was able to discover that it was probably failing due to a lock file that it wasn't expecting to be present /tmp/qtsingleapp-OctoPk-df17-3e9-lockfile
?.
57260 octopkg CALL mmap(0,0x10000,0x7<PROT_READ|PROT_WRITE|PROT_EXEC>,0x1002<MAP_PRIVATE|MAP_ANON>,0xffffffff,0)
57260 octopkg RET mmap 34454446080/0x805a52000
57260 octopkg CALL getuid
57260 octopkg RET getuid 1001/0x3e9
57260 octopkg CALL fstatat(AT_FDCWD,0x805a12a38,0x7fffffffe1c0,0x200<AT_SYMLINK_NOFOLLOW>)
57260 octopkg NAMI "/tmp"
57260 octopkg STRU struct stat {dev=1688810132604225836, ino=4, mode=041777, nlink=24, uid=0, gid=0, rdev=18446744073709551615, atime=1547866952, mtime=1552090801.781472000, ctime=1552090801.781472000, birthtime=1544155858, size=96, blksize=16384, blocks=65, flags=0x800 }
57260 octopkg RET fstatat 0
57260 octopkg CALL openat(AT_FDCWD,0x8033e7b18,0x100202<O_RDWR|O_CREAT|O_CLOEXEC>,0666<S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH>)
57260 octopkg NAMI "/tmp/qtsingleapp-OctoPk-df17-3e9-lockfile"
57260 octopkg RET openat 9
57260 octopkg CALL fcntl(0x9,F_SETLK,0x7fffffffe4c0)
57260 octopkg RET fcntl -1 errno 35 Resource temporarily unavailable
57260 octopkg CALL fcntl(0x9,F_SETLK,0x7fffffffe420)
57260 octopkg RET fcntl -1 errno 35 Resource temporarily unavailable
57260 octopkg CALL socket(PF_LOCAL,0x30000001<SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK>,0)
57260 octopkg RET socket 10/0xa
57260 octopkg CALL fstatat(AT_FDCWD,0x805a12ab8,0x7fffffffe100,0x200<AT_SYMLINK_NOFOLLOW>)
57260 octopkg NAMI "/tmp"
57260 octopkg STRU struct stat {dev=1688810132604225836, ino=4, mode=041777, nlink=24, uid=0, gid=0, rdev=18446744073709551615, atime=1547866952, mtime=1552090801.781472000, ctime=1552090801.781472000, birthtime=1544155858, size=96, blksize=16384, blocks=65, flags=0x800 }
57260 octopkg RET fstatat 0
57260 octopkg CALL connect(0xa,0x7fffffffe400,0x6a)
57260 octopkg STRU struct sockaddr { AF_LOCAL, /tmp/qtsingleapp-OctoPk-df17-3e9 }
57260 octopkg NAMI "/tmp/qtsingleapp-OctoPk-df17-3e9"
57260 octopkg RET connect 0
57260 octopkg CALL getsockname(0xa,0x7fffffffe2c0,0x7fffffffe2ec)
57260 octopkg STRU struct sockaddr { AF_LOCAL, }
57260 octopkg RET getsockname 0
57260 octopkg CALL getpeername(0xa,0x7fffffffe2c0,0x7fffffffe2ec)
57260 octopkg STRU struct sockaddr { AF_LOCAL, /tmp/qtsingleapp-OctoPk-df17-3e9 }
57260 octopkg RET getpeername 0
57260 octopkg CALL getsockopt(0xa,SOL_SOCKET,SO_TYPE,0x7fffffffe2a0,0x7fffffffe2e8)
57260 octopkg RET getsockopt 0
57260 octopkg CALL fcntl(0xa,F_GETFL)
57260 octopkg RET fcntl 6
57260 octopkg CALL fcntl(0xa,F_SETFL,0x6<O_RDWR|O_NONBLOCK>)
57260 octopkg RET fcntl 0
57260 octopkg CALL write(0x7,0x7fffffffe23f,0x1)
57260 octopkg GIO fd 7 wrote 1 byte
0x0000 01 |.|
57260 octopkg RET write 1
57260 octopkg CALL mmap(0,0xb000,0x3<PROT_READ|PROT_WRITE>,0x1002<MAP_PRIVATE|MAP_ANON>,0xffffffff,0)
57260 octopkg RET mmap 34454360064/0x805a3d000
57260 octopkg CALL write(0x7,0x7fffffffe31f,0x1)
57260 octopkg GIO fd 7 wrote 1 byte
0x0000 01