Is Scalingo Buildpack Cache Invalidate When Dependency Changes?

Background

Scalingo keeps a per‑application buildpack cache to speed up subsequent builds. The cache persists until the user clears it via the CLI or dashboard. Current documentation does not state that the cache is automatically refreshed when a dependency manifest (e.g., Gemfile, package.json, Pipfile) is modified.

Unresolved Decision

When a dependency version is updated in the manifest but the lock file remains unchanged, it is unclear whether the cached buildpack will still serve the old artifact. Users must manually clear the cache to force a rebuild, which increases build time and resource consumption.

Questions

• Does Scalingo automatically invalidate the buildpack cache when a dependency manifest changes, or does it rely solely on the buildpack’s internal logic?
• Can the cache be configured with a TTL or disabled entirely to avoid stale results?
• What is the effect on build time and resource usage when the cache is cleared versus when it is left intact?