Here is the strace for the dist/IO/t/io_sock.t test: http://pastebin.ca/2670056

Looking through it, I'm not sure whether to be alarmed by all the illegal seeks or inappropriate ioctls. I can see the arguments for the system calls as bellow. This is a snippet of the full log above.

4162  socket(PF_INET, SOCK_STREAM, IPPROTO_TCP) = 4
4162  ioctl(4, TIOCNXCL, 0x7f8dd7b0)    = -1 EINVAL (Invalid argument)
4162  _llseek(4, 0, 0x7f8dd7d0, SEEK_CUR) = -1 ESPIPE (Illegal seek)
4162  ioctl(4, TIOCNXCL, 0x7f8dd7b0)    = -1 EINVAL (Invalid argument)
4162  _llseek(4, 0, 0x7f8dd7d0, SEEK_CUR) = -1 ESPIPE (Illegal seek)
4162  fcntl64(4, F_SETFD, FD_CLOEXEC)   = 0
4162  connect(4, {sa_family=AF_INET, sin_port=htons(50346), sin_addr=i
+net_addr("127.0.0.1")}, 16) = 0
4161  <... stat64 resumed> 0x7f8dd740)  = -1 ENOENT (No such file or d
+irectory)
4162  write(4, "ok 3\n", 5 <unfinished ...>
4161  stat64("/media/9b24938d-ae9c-4776-98a2-ba1863c3efc3/usr/lib/perl
+5/site_perl/5.18.2/IO/Select.pm",  <unfinished ...>
4162  <... write resumed> )             = 5
4161  <... stat64 resumed> 0x7f8dd660)  = -1 ENOENT (No such file or d
+irectory)
4162  brk(0x801000 <unfinished ...>
4161  stat64("/media/9b24938d-ae9c-4776-98a2-ba1863c3efc3/usr/lib/perl
+5/5.18.2/mips-linux/IO/Select.pmc",  <unfinished ...>
4162  <... brk resumed> )               = 0x801000
4161  <... stat64 resumed> 0x7f8dd740)  = -1 ENOENT (No such file or d
+irectory)
4162  read(4,  <unfinished ...>
4161  stat64("/media/9b24938d-ae9c-4776-98a2-ba1863c3efc3/usr/lib/perl
+5/5.18.2/mips-linux/IO/Select.pm", {st_mode=S_IFREG|0444, st_size=824
+7, ...}) = 0
4161  open("/media/9b24938d-ae9c-4776-98a2-ba1863c3efc3/usr/lib/perl5/
+5.18.2/mips-linux/IO/Select.pm", O_RDONLY|O_LARGEFILE) = 4
4161  ioctl(4, TIOCNXCL, 0x7f8dd508)    = -1 ENOTTY (Inappropriate ioc
+tl for device)
4161  _llseek(4, 0, [0], SEEK_CUR)      = 0
4161  brk(0x801000)                     = 0x801000
4161  read(4, "# IO::Select.pm\n#\n# Copyright (c"..., 8192) = 8192
4161  brk(0x803000)                     = 0x803000
4161  brk(0x804000)                     = 0x804000
4161  brk(0x805000)                     = 0x805000
4161  brk(0x806000)                     = 0x806000
4161  brk(0x807000)                     = 0x807000
4161  brk(0x808000)                     = 0x808000
4161  brk(0x80a000)                     = 0x80a000
4161  brk(0x80b000)                     = 0x80b000
4161  brk(0x80c000)                     = 0x80c000
4161  brk(0x80d000)                     = 0x80d000
4161  brk(0x80e000)                     = 0x80e000
4161  brk(0x80f000)                     = 0x80f000
4161  brk(0x810000)                     = 0x810000
4161  brk(0x811000)                     = 0x811000
4161  brk(0x812000)                     = 0x812000
4161  brk(0x814000)                     = 0x814000
4161  brk(0x815000)                     = 0x815000
4161  _llseek(4, 4259, [4259], SEEK_SET) = 0
4161  _llseek(4, 0, [4259], SEEK_CUR)   = 0
4161  close(4)                          = 0
4161  getuid()                          = 0
4161  geteuid()                         = 0
4161  getgid()                          = 0
4161  getegid()                         = 0
4161  _newselect(8, [], NULL, NULL, {15, 0}) = 0 (Timeout)
4161  write(2, "accept failed: Connection timed "..., 89) = 89
[download]

The arguments look ok to me, at least they're not corrupted somehow.

I've also compiled perl using buildroot (which also uses perl-cross) and have compared the config.log files. One thing which leaps out is the buildroot perl doesn't enable Duselargefiles. I've modified my configure call to also disable large file support, but no improvement.

The only other differences was a couple of floating point system calls being unavailable with my toolchain, which I'm ASSuming are unrelated to this.

Ok I think I'm being too precious about these tests passing, I now see that the reason the Socket.t test fails is that my router doesn't listen on port 7 - hence 'connection refused' in the strace.

Looking through strace on the actual failing application, I can see the issue is missing modules. LWP not finding Net::HTTP being one of them. I will rebuild my perl installation and monitor strace for missing modules.

I presumed I'd get some sort of warning on the command line, sorry I'm still an amateur with perl..