s3fs uses reticulate/Python which significantly increases R process memory.
When pak tries to fork R to install package dependencies, the enlarged
process can't be duplicated within the container memory limit.
Now the install-deps step saves the S3 file listing as s3_cache.rds,
and the build step reads it with readRDS() — no s3fs loading needed.
- Load bincraft eagerly via library() to avoid lazy-load memory spike
- Do bulk S3 listing upfront and pass as s3_package_cache to avoid
per-package S3 calls that accumulate memory and trigger fork failures
- Consolidate amd64/arm64 exclude lists into single script
- Much easier to read and maintain than a YAML-embedded one-liner
