## Summary
- When building via `nix build`, the binary reports `codex-cli 0.0.0`
because the workspace `Cargo.toml` uses `0.0.0` as a placeholder on
`main`. This causes the update checker to always prompt users to upgrade
even when running the latest code.
- Reads the version from `codex-rs/Cargo.toml` at flake evaluation time
using `builtins.fromTOML` and patches it into the workspace `Cargo.toml`
before cargo builds via `postPatch`.
- On release commits (e.g. tag `rust-v0.101.0`), the real version is
used as-is. On `main` branch builds, falls back to
`0.0.0-dev+<shortRev>` (or `0.0.0-dev+dirty`), which the update
checker's `parse_version` ignores — suppressing the spurious upgrade
prompt.
| Scenario | Cargo.toml version | Nix `version` | Binary reports |
Upgrade nag? |
|---|---|---|---|---|
| Release commit (e.g. `rust-v0.101.0`) | `0.101.0` | `0.101.0` |
`codex-cli 0.101.0` | Only if newer exists |
| Main branch (committed) | `0.0.0` | `0.0.0-dev+b934ffc` | `codex-cli
0.0.0-dev+b934ffc` | No |
| Main branch (uncommitted) | `0.0.0` | `0.0.0-dev+dirty` | `codex-cli
0.0.0-dev+dirty` | No |
## Test plan
- [ ] `nix build` from `main` branch and verify `codex --version`
reports `0.0.0-dev+<shortRev>` instead of `0.0.0`
- [ ] Verify the update checker does not show a spurious upgrade prompt
for dev builds
- [ ] Confirm that on a release commit where `Cargo.toml` has a real
version, the binary reports that version correctly
I dropped the build of the old cli from the flake, where the default.nix
already seemed to removed in a previous iterations. Then I updated
flake.nix and codex-rs expression to be able to build again (see
individual commits for details).
Tested by running the following builds:
```
$ nix build .#packages.x86_64-linux.codex-rs
$ nix build .#packages.aarch64-darwin.codex-cli
```
---------
Signed-off-by: Jörg Thalheim <joerg@thalheim.io>
Right now since the repo is having two different implementations of
codex, flake was updated to work with both typescript implementation and
rust implementation
This PR introduces a Nix flake configuration to enable reproducible
development environments:
- Adds flake.nix defining a devShell with necessary dependencies.
- Updates README.md with usage instructions for `nix develop`.
- Ensures CI compatibility with Nix for consistent builds.
