Re: Build particular Rust version

[Csepp <raingloom@riseup.net>]

Matthew James Kraai <kraai@ftbfs.org> writes:

> Hi,
>
> Is it possible to build Rust 1.58.1 without updating the `rust`
> definition?  If so, how do I do so?
>
> If I apply this patch:
>
> ```
> diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
> index 67dc5cdaf3..61d6686b64 100644
> --- a/gnu/packages/rust.scm
> +++ b/gnu/packages/rust.scm
> @@ -644,10 +644,14 @@ (define rust-1.56
>     rust-1.55 "1.56.1" "04cmqx7nn63hzz7z27b2b0dj2qx18rck9ifvip43s6dampx8v2f3"))
>  
>  (define rust-1.57
> +  (rust-bootstrapped-package
> +   rust-1.56 "1.57.0" "06jw8ka2p3kls8p0gd4p0chhhb1ia1mlvj96zn78n7qvp71zjiim"))
> +
> +(define rust-1.58
>    (let ((base-rust
>           (rust-bootstrapped-package
> -          rust-1.56 "1.57.0"
> -          "06jw8ka2p3kls8p0gd4p0chhhb1ia1mlvj96zn78n7qvp71zjiim")))
> +          rust-1.57 "1.58.1"
> +          "1iq7kj16qfpkx8gvw50d8rf7glbm6s0pj2y1qkrz7mi56vfsyfd8")))
>      (package
>        (inherit base-rust)
>        (outputs (cons "rustfmt" (package-outputs base-rust)))
> ```
>
> and run `./pre-inst-env guix build rust@1.58.1`, it outputs
>
> ```
> guix build: error: rust: package not found for version 1.58.1
> ```

I haven't tried building Rust, but at a glance it seems like the new
package inherits its version field from base-rust.
Guix doesn't really care what symbol you assign the package to, only the
version field matters.  You could write (define-public
this-is-definitely-php rust-base) and it would still show up in `guix
search rust`.