So I had this problem where I 'tail'-ed a file, and 'awk'-ed the results, and that worked fine.
After that I wanted to further 'sed' the outcome of the 'awk', and there's where things went wrong, i.e. no output.
So after a decent search I found that 'awk' buffers the output, and I had to 'unbuffer' that. Some 'awk's seem to have an option to switch that on or off, but not on FreeBSD (at least, I didn't find it). So I found something cool:
Put this in front of the buffering command unbuffers the output, and then things start working again: