version lockstepping

[jhheider]

some packages require (or nearly require) being in version lockstep with another package. the example we have today are all the facebook libraries, which release weekly, use calver, and constantly break compatibility.

perhaps something like:

dependencies:
  github.com/facebookincubator/fizz: sync
  facebook.com/folly: sync
  facebook.com/wangle: sync

where sync could be match, lock, version, or {{version}}. it complicates the solver, but is a very specific class of per-version versioning that shouldn't be awful.

[mxcl]

{{version}} seems correct if it matches the version of the package.yml. Am I getting you?

[jhheider]

yes. just trying to think about both UX and resolverX.