[Bug]: Build failure following "How To".

[neilg]

Current Behavior

Following the instructions at https://jupyenv.io/documentation/how-to/ leads to a build failure:

nix flake init --template github:tweag/jupyenv
nix run

leads to

evaluation warning: rustPlatform.fetchCargoTarball is deprecated in favor of rustPlatform.fetchCargoVendor.
                    If you are using buildRustPackage, try setting useFetchCargoVendor = true and regenerating cargoHash.
                    See the 25.05 release notes for more information.
error: hash mismatch in fixed-output derivation '/nix/store/9wn2wh7xwamdig9w7h7wvcdil39c1jjq-rpds-py-0.21.0-vendor.tar.gz.drv':
         specified: sha256-VOmMNEdKHrPKJzs+D735Y52y47MubPwLlfkvB7Glh14=
            got:    sha256-EDIJw2lZ5nhANTp8bdkkyeSMHD2btHZ+IeN2ROkJN9o=
error: 1 dependencies of derivation '/nix/store/1cv85v4cgsrdn12ihi484wwnssr0gxsi-python3.12-rpds-py-0.21.0.drv' failed to build
error: 1 dependencies of derivation '/nix/store/hvw8fc6vzafpqwbw6j4qivq74l8ki19h-python3-3.12.9-env.drv' failed to build
error: 1 dependencies of derivation '/nix/store/b52whimw7ich1qzdyyaz0wqi9hlkzc9v-chmod-python3-3.12.9-env.drv' failed to build
error: 1 dependencies of derivation '/nix/store/g14wk29ckz89jbyf6whsd600ylhzaizs-wrapper-chmod-python3-3.12.9-env.drv' failed to build

Expected Behavior

The command should complete successfully.

Steps To Reproduce

nix flake init --template github:tweag/jupyenv
nix run

OS

- system: `"x86_64-linux"`
 - host os: `Linux 6.13.3, NixOS, 25.05 (Warbler), 25.05.20250221.32fb99b`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.26.2`
 - channels(root): `"nixos-24.05"`
 - nixpkgs: `/nix/store/qc7n2v5yl42m2wq59f59ly6igiwljh11-source`

Version

Latest main: 55e42c3

Additional Context

I'm not sure if this output early in the build is relevant:

warning: ignoring untrusted substituter 'https://tweag-jupyter.cachix.org', you are not a trusted user.
Run `man nix.conf` for more information on the `substituters` configuration option.
warning: ignoring the client-specified setting 'trusted-public-keys', because it is a restricted setting and you are not a trusted user

Relevant log output