8.8. Managing Published Scala Dependencies

In preparation for Chisel 3.5, in Chipyard 1.5 Chisel, FIRRTL, the FIRRTL interpreter, and Treadle, were transitioned from being built-from-source to managed as published dependencies. Their submodules have been removed. Switching between published versions can be achieved by changing the versions specified in Chipyard’s build.sbt.

Lists of available artifacts can be using search.maven.org or mvnrepository.org:

8.8.1. Publishing Local Changes

Under the new system, the simplest means to make custom source modifications to the packages above is to run sbt +publishLocal from within a locally modified clone of each of their respective repositories. This will post your custom variant to your local ivy2 repository, which can generally be found at ~/.ivy2. See the SBT documentation for more detail.

In practice, this will require the following steps:

  1. Check out and modify the desired projects.
  2. Take note of, or modify, the versions of each projects (in their build.sbt). If you’re cloning from master generally these will have default versions of 1.X-SNAPSHOT, where X is not-yet-released next major version. You can modify the version string, to say 1.X-<MYSUFFIX>, to uniquely identify your change.
  3. Call sbt +publishLocal in each subproject. You may need to rebuild other published dependencies. SBT will be clear about what it is publishing and where it is putting it. The + is generally necessary and ensures that all cross versions of the package are published.
  4. Update the Chisel or FIRRTL version in Chipyard’s build.sbt to match the versions of your locally published packages.
  5. Use Chipyard as you would normally. Now when you call out to make in Chipyard you should see SBT resolving dependencies to the locally published instances in your local ivy2 repository.
  6. When you’re finished, consider removing your locally published packages (by removing the appropriate directory in your ivy2 repository) to prevent accidentally reusing them in the future.

A final word of caution: packages you publish to your local ivy repository will be visible to other projects you may be building on your system. For example, if you locally publish Chisel 3.5.0, other projects that depend on Chisel 3.5.0 will preferentially use the locally published variant over the version available on Maven (the “real” 3.5.0). Take care to note versions you are publishing and remove locally published versions once you are done with them.