@elite-dangerous-almanac/core / ships / ModuleFitConstraint

ModuleFitConstraint = "immutableSlot" | "builtInHullModule" | "armourRequired" | "wrongHullArmour" | "restrictedHull" | "restrictedMount" | "wrongCoreType" | "hardpointRequired" | "utilityRequired" | "optionalInternalRequired" | "coreModuleInOptionalSlot" | "oversized" | "exactSizeRequired" | "unknownConstraint"

Defined in: src/ships/loadout-validation.ts:58

Stable machine-readable constraint behind an incompatibleModule issue.

builtInHullModule is the only one that does not depend on the mount: the cargo hatch comes with the hull and goes in no mount an editor can set.