CLI Behavior for sipnet/model binary resolution

[hdpriest-ui]

We currently support two primary run modes for the workflow:

1. Apptainer-contained Slurm — The SIPNET binary ships inside the container image. We don't need to download or install anything for this approach.

2. Host-native conda/Slurm — The SIPNET binary must be present on the host filesystem at a known path before any ensemble jobs can run. This is currently handled by tools/install_sipnet.sh, which clones the source repo and compiles via make sipnet.

This discussion is concerned with the 2nd use case.

In both options below; we will first allow the user to provide a local sipnet binary, and if that isn't the preferred option, we will obtain a copy of it via the below method(s)

Option A — Compile from source (current approach)

Clone PecanProject/sipnet, check out the target revision, and compile locally. The script is idempotent and stores versioned binaries by git hash.

Obviously, this takes more time, and could run into compile-tool issues (in theory, but probably not in practice)

Option B — Fetch a pre-compiled binary from GitHub Releases

Discover available releases and download the appropriate binary via the GitHub REST API using plain curl. We would want to avoid using the gh cli; as this might not be available in the target environment. Curl will work just fine:

# List releases and their assets
curl -s "https://api.github.com/repos/PecanProject/sipnet/releases" \
  | jq '.[] | {tag: .tag_name, assets: [.assets[]? | {name, url: .browser_download_url}]}'

# Download a specific binary asset (follows redirect to S3)
curl -fsSL -o sipnet_<tag> "<browser_download_url>"

# note that the actual invoked method will probably differ from this.

We could allow the user to specify the sipnet version they wish to obtain for a particular run - this would enable the use of the most-recent version as standard, but also allow us to provision special-sauce versions if we need to deliver pre-production functionality for some reason.

In short, the install script would resolve the desired release, pull the matching binary, store it under the versioned naming convention already used by install_sipnet.sh, and symlink it into place — matching the existing idempotent install pattern.

No compile required, just a download and a link. Depends on us being disciplined about the content of the binaries in github, and requires curl and jq to be present on the install environment (easily resolved)

tl,dr; we should probably go with Option B.

[hdpriest-ui]

@dlebauer ; @infotroph ; @Alomir : will go forward with option B, download of binary to the run directory.