Derivations created using this repository are not reproducible

[sleirsgoevy]

Specifying "nightly" rust in buildInputs of my package causes the latest nightly Rust to be downloaded each time I try to build the package. Please consider pinning specific commits of this repository to specific versions of Rust, so that version pinning becomes possible.

[nbp]

This is not the goal of this repository to pin a specific nightly.
If we were pinning any version, then the nightly version would no longer be the latest, as intended.

One thing which can be done, would be to generate a nix expression from the manifest file, and which relies on function provided by this repository to provide a pin-like behavior, but this would no longer be the latest. This would be one random version which happened to have been the nightly for a day.

[Artturin]

@colemickens has made a reproducible flake for firefox-nightly so i assume the same thing could be done for rust https://github.com/colemickens/flake-firefox-nightly