mirror of
https://github.com/ipetkov/crane.git
synced 2024-11-23 08:22:41 +03:00
20 lines
1.1 KiB
Markdown
20 lines
1.1 KiB
Markdown
|
## Philosophy
|
||
|
|
|
||
|
|
Crane is designed around the idea of composing cargo invocations such that they
|
||
|
|
can take advantage of the artifacts generated in previous invocations. This
|
||
|
|
allows for both flexible configurations and great caching (à la Cachix) in CI
|
||
|
|
and local development builds.
|
||
|
|
|
||
|
|
Here's how it works at a high level: when a cargo workspace is built its source
|
||
|
|
is first transformed such that only the dependencies listed by the `Cargo.toml`
|
||
|
|
and `Cargo.lock` files are built, and none of the crate's real source is
|
||
|
|
included. This allows cargo to build all dependency crates and prevents Nix from
|
||
|
|
invalidating the derivation whenever the source files are updated. Then, a
|
||
|
|
second derivation is built, this time using the real source files, which also
|
||
|
|
imports the cargo artifacts generated in the first step.
|
||
|
|
|
||
|
|
This pattern can be used with any arbitrary sequence of commands, regardless of
|
||
|
|
whether those commands are running additional lints, performing code coverage
|
||
|
|
analysis, or even generating types from a model schema. Let's take a look at two
|
||
|
|
examples at how very similar configurations can give us very different behavior!
|