docs/rust: describe cargoHash

This commit is contained in:
Daniël de Kok 2020-12-03 09:39:39 +01:00
parent 67a10c88bb
commit b6728fa15c

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@ -27,16 +27,16 @@ Rust applications are packaged by using the `buildRustPackage` helper from `rust
``` ```
rustPlatform.buildRustPackage rec { rustPlatform.buildRustPackage rec {
pname = "ripgrep"; pname = "ripgrep";
version = "11.0.2"; version = "12.1.1";
src = fetchFromGitHub { src = fetchFromGitHub {
owner = "BurntSushi"; owner = "BurntSushi";
repo = pname; repo = pname;
rev = version; rev = version;
sha256 = "1iga3320mgi7m853la55xip514a3chqsdi1a1rwv25lr9b1p7vd3"; sha256 = "1hqps7l5qrjh9f914r5i6kmcz6f1yb951nv4lby0cjnp5l253kps";
}; };
cargoSha256 = "17ldqr3asrdcsh4l29m3b5r37r5d0b3npq1lrgjmxb6vlx6a36qh"; cargoSha256 = "03wf9r2csi6jpa7v5sw5lpxkrk4wfzwmzx7k3991q3bdjzcwnnwp";
meta = with stdenv.lib; { meta = with stdenv.lib; {
description = "A fast line-oriented regex search tool, similar to ag and ack"; description = "A fast line-oriented regex search tool, similar to ag and ack";
@ -47,10 +47,31 @@ rustPlatform.buildRustPackage rec {
} }
``` ```
`buildRustPackage` requires a `cargoSha256` attribute which is computed over `buildRustPackage` requires either the `cargoSha256` or the
all crate sources of this package. Currently it is obtained by inserting a `cargoHash` attribute which is computed over all crate sources of this
fake checksum into the expression and building the package once. The correct package. `cargoHash256` is used for traditional Nix SHA-256 hashes,
checksum can then be taken from the failed build. such as the one in the example above. `cargoHash` should instead be
used for [SRI](https://www.w3.org/TR/SRI/) hashes. For example:
```
cargoHash = "sha256-l1vL2ZdtDRxSGvP0X/l3nMw8+6WF67KPutJEzUROjg8=";
```
Both types of hashes are permitted when contributing to nixpkgs. The
Cargo hash is obtained by inserting a fake checksum into the
expression and building the package once. The correct checksum can
then be taken from the failed build. A fake hash can be used for
`cargoSha256` as follows:
```
cargoSha256 = stdenv.lib.fakeSha256;
```
For `cargoHash` you can use:
```
cargoHash = stdenv.lib.fakeHash;
```
Per the instructions in the [Cargo Book](https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html) Per the instructions in the [Cargo Book](https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html)
best practices guide, Rust applications should always commit the `Cargo.lock` best practices guide, Rust applications should always commit the `Cargo.lock`