Julia version pinning absent from Manifest.toml resolution lock

Direct answer

Manifest.toml does not record the Julia patch version used for resolution, so a julia_version field should not be added; the required Julia version must be enforced outside the lock file.

Confirmed facts

The Manifest.toml format stores package UUIDs, versions, and git SHAs only. Project.toml may contain a julia = "1.9" constraint, which limits the major/minor range but does not lock a specific patch (e.g., 1.9.3 vs 1.9.4). Consequently, the same Manifest.toml can yield different dependency graphs when instantiated on a newer Julia patch, breaking bit‑for‑bit reproducibility.

Likely explanation

Teams often assume that adding a dedicated field would solve the problem, but the file schema is fixed and extending it would conflict with existing parsers and tooling. Therefore, reproducibility must be guaranteed by external mechanisms rather than by modifying the lock file itself.

Recommended workflow

1. Record the exact Julia patch version in your CI configuration or a wrapper script that runs before Pkg.instantiate(). Example in a CI step:
2. ```bash export JULIA_VERSION=1.9.3 # version used when Manifest.toml was generated julia --project -e 'using Pkg; Pkg.instantiate()' ```
3. Document this version in the project’s README and require developers to run the same version locally, or use a version manager (e.g., `juliaenv`, `asdf`) to enforce it.
4. Optionally, add a small pre‑instantiation check in a custom script that aborts if the running Julia version differs from the recorded one.

Missing diagnostic

To verify that the current environment matches the original resolution, please provide the exact Julia patch version that was active when the Manifest.toml was generated.