add --verbose flag so I can watch pip-compile progress

[graingert]

jazzband/pip-tools#521

[peterdemin]

I've read the linked issue, and my understanding of the problem is that at times pip-tools runs extremely slow and it's hard to tell if it's making any progress (correct me if I'm wrong).
While having a progress bar might look nice, I feel like this feature will make code harder to maintain without any adding practical benefit.
I'm closing the issue, but feel free to reopen with a good argument.

[graingert]

Even without the progress bars it's good to be able to see what package is taking a long time

[peterdemin]

Yeah, must be feeling good, but how does this information help? I mean, there is no way to speed up any particular package. pip-tools will take as much time as it needs. And the slow package will be slow during installation too, so it's not an insight.

[graingert]

@peterdemin I don't really care too much about the progress bar, just some sort of verbose output

sometimes I end up with pathological cases where it's sat retrying because I forgot to connect to the VPN

[peterdemin]

I'll be happy to review the PR with this feature. -v/—verbose that streams live pip-tools progress.

[john-sandall]

@graingert Stumbled across this issue whilst searching for exactly the same feature. I've sketched out a partial solution in #247, reckon it's got legs?

[john-sandall]

Closed by #251?

[peterdemin]

Yes, thanks!