ADR 0076 — A package's compiler requirement: ceesafec = ">=0.19.1"

• Status: Accepted by the owner, 2026-11-06 ("yes", to adding the key so CosmoStore's manifest can pin 0.19.1). Raised by the CosmoStore port (CeeSafeApps/cosmostore/CEESAFE_GAPS.md G23).
• Scope: tooling.md §4.1 and §4.5, src/packages/manifest.cee, guide/packages.md, the package tests.

1. Context

CosmoStore needs ceesafec 0.19.1: File.readAt and the other durable methods take borrow this from that release on (ADR 0075 §8). Under 0.19.0, ceesafec check reports 12 errors in durable.cee, the first one N0248, and nothing in them says that a newer compiler would accept the package. A manifest has no way to state the compiler it needs.

2. Decision

1. [package] takes ceesafec = "<requirement>", a version requirement in the dependencies' syntax (§4.7):
   • comparators separated by commas, all of which must hold (>=0.19.1, >=0.19.1, <0.20.0);
   • 1.4 or ^1.4 is a caret requirement;
   • * is any version.
2. When the manifest is read (check, build, run, test, fetch, and a dependency's manifest as the root's), a compiler whose version does not satisfy the requirement reports N0321 at the value, before anything is checked: this package needs ceesafec >=0.19.1; this is ceesafec 0.19.0. A requirement that does not parse is N0321 with the field's shape.
3. A development version (0.20.0-dev) is compared as its MAJOR.MINOR.PATCH.
4. A compiler older than this ADR reports unknown field 'ceesafec' in [package] (N0321) at the same line, which still points the reader at the requirement.

3. Not included

• Choosing or downloading a compiler: the field states a requirement, and the reader acts on it.
• A requirement on lib/core or lib/std alone: they ship with the compiler, so its version covers them.