Building multiple packages is broken

[rburchell]

Discovered while playing around with #13.

If I do: multibuild ./cmd/one ./cmd/two

Then I get errors due to #13, but even once that is fixed, the ultimate result will be weird (at best) or a failure at worst, because we'll build a command line go build ./cmd/one ./cmd/two -o ./cmd/two (or something like that) which ... just no, you can't build two binaries at once like that.

I'm not entirely sure how go build deals with this. It looks like it might try build the packages, but not produce an output binary. That might be a sensible course of action to take.

[rburchell]

Ok, I was wrong.

go build ./cmd/one ./cmd/two -o foo -> malformed import path "-o": leading dash
go build -o foo ./cmd/one ./cmd/two -> go: cannot write multiple packages to non-directory foo
mkdir foo; go build -o foo ./cmd/one ./cmd/two -> succeeds, and places binaries in foo

So then we have to do the same: put our -o first, then the paths.