How to set duration for avconv?
I can reproduce this issue (trying to use avconv to convert 20 seconds of internet radio stream into a wav file). So here's a fix which worked for me: simply permute the -t and -i options!
In your case, I'm suggesting trying
ffmpeg -i GOPR0001.MP4 -t 10 cut.MP4
I'm also suggesting that someone files a bug report.
EDIT: in fact it's not a bug -- it's a feature!
https://bugzilla.libav.org/show_bug.cgi?id=399
Apparently the bug was in ffmpeg ;-) The logic is apparently that -t is an output option, so should go after the input options. Go figure.