[swift-evolution] [swift-build-dev] [Proposal] Lock file for Swift Package Manager

[Adam Sharp]

> On 23 Dec 2015, at 9:28 AM, Joshua Scott Emmons via swift-build-dev <swift-build-dev at swift.org> wrote:
> 
> There are three things that should be possible at this point:
> 1. Build with the existing v1.1 dep.
> 2. Update deps to the lockfile version (v1.2).
> 3. Update deps and lockfile to the latest conforming version (1.3).

It looks like the difference here between spm and the other dependency managers I'm familiar with (CocoaPods and Bundler) is that here we've got a single action ("build") that both installs dependencies and builds them, whereas in the others there is an "install" step that is separate.

Because those two things are combined into the one command, it's impossible for spm to correctly guess the user's intent in all situations. There may be a sensible default, however.

–Adam