# Task B1 Report: Create the patch registry with the RcppParallel entry

## Status: Completed

All steps completed successfully.

## Files Created

1. **`local/patches/registry.json`**
   - Contains the curated patch registry array with one entry for RcppParallel
   - Entry specifies platform-specific build-time override: `RCPP_PARALLEL_USE_TBB=0` environment variable for alpine and ubuntu-2604
   - No source diff needed; the fix is purely an environment variable override

2. **`local/patches/README.md`**
   - Documents the JSON schema with field semantics copied from the design spec
   - Provides instructions on how to add new patch entries
   - Explains that source diffs go in `local/patches/<pkg>/<file>.patch` and are referenced by the `patch` field
   - Includes validation instructions using R

## Verification

Ran the verification R script:

```r
Rscript -e 'x <- jsonlite::fromJSON("local/patches/registry.json", simplifyVector = FALSE); stopifnot(length(x) == 1L, x[[1]]$package == "RcppParallel"); cat("ok\n")'
```

Output: `ok`

The JSON parses correctly, contains exactly one entry, and the package name is "RcppParallel" as expected.

## Commit

```
5bf9b2e feat(patches): add patch registry with RcppParallel TBB workaround
```

Branch: `t3code/patch-packages-before-build`

Both files were staged and committed with the message specified in the task brief.