Migrating to v0.2

Major behavioral changes in v0.2:

1. Werk no longer distinguishes between “workspace” and “out-dir” directories. Instead, all paths are relative to the workspace directory. The motivation for this change is to make it easier to implement manually initiated workflows that generate output files that are committed to source control, such as bindgen output and the like. But it means that Werkfiles must now explicitly put build artifacts in the desired output directory (/target for Rust projects etc.). This change also means that the string interpolation ops <...:out-dir> and <...:workspace> no longer work, and will cause errors.

2. Werk no longer implicitly uses <root>/target as the location for the cache when no other directory is configured in the Werkfile or on the command-line.

3. All recipes are now fully evaluated before any build commands are executed. This catches errors earlier, and allows for an internal “planning” step that can produce more interesting output (like a .dot dependency graph), but it also removes most chances of having recipes interfere with each other’s evaluation.

werk will fatally error if it detects a v0.1-style Werkfile containing a default out-dir = ... directive, or if the output-dir option is passed on the command-line.

Steps to migrate:

1. Change all build recipes to place their outputs in the desired output directory (/target for Rust projects etc.).

2. Change default out-dir = ... directives in your Werkfile to default cache-dir = ... to place the .werk-cache in the same location.