Author	SHA1	Message	Date
pat-s	af4cc6f414	feat(ci): verify what clients actually receive from every published slot (#209) ... ## Why Everything built so far reasons about the *binaries*: `abi_flat_safety` records what an object's symbols say it can load under, and the index writer drops records on that verdict. None of it proves what a **client** actually receives, which is the product of the CDN rewrite, the per-minor indexes and the `Path:` field acting together. The reprex that found the `base64enc` failure ran on a workstation, could only reach amd64, and did not survive the session. This makes it a pipeline. ## What it does For every slot, under every R minor the image carries, it installs a fixed package set through each URL form the website documents and checks that each one loads in a fresh subprocess. | form | repository | user agent | | --- | --- | --- | | `arch` | `https://cran.rpkgs.com/<arch>/<codename>/latest` | R's own | | `generic` | `https://cran.rpkgs.com/` | the string the website's snippet builds | | `flat` | the arch URL | `curl/8.5.0`, so the edge cannot read an R minor | `arch` and `generic` are contractual, so a failure there fails the run. `flat` measures what a client hiding its R minor is exposed to: it is reported and never fatal, because pruning the flat slot is a separate decision. Two details that matter: - **CRAN is deliberately absent from `repos`.** A package missing from our index must fail loudly rather than be quietly compiled from source, which would hide exactly the gap this exists to find. - **One process per form.** `available.packages()` caches its index in `tempdir()` keyed by repository URL, and `arch` and `flat` share a URL. In a single process the second form would read the first form's index and prove nothing. ## Verification Run against the live repository in `build-env-ubuntu:noble` under R 4.6.0, mid-repair: ``` amd64/noble R 4.6 via arch: 11 of 11 packages usable amd64/noble R 4.6 via generic: 11 of 11 packages usable amd64/noble R 4.6 via flat: 8 of 11 packages usable ``` The three `flat` failures are `Rcpp`, `data.table` and `yaml`, each `Built: R 4.4.3` and each failing `dyn.load()` under 4.6. That is the unrouted-client exposure, measured rather than estimated. The rows also show the routed forms serving a mix of per-minor and flat objects (`Rcpp` at `R 4.6.0`, `stringi` at `R 4.4.3`), which is the intended behaviour: only objects that cannot load cross-minor get a per-minor copy. Reviewed-on: #209	2026-09-09 12:52:16 +00:00