GHC 10.0.0.20260917 · lts/ghc-10.0.x · 04404a6 · 2026-10-19
Moduleghc-10.0.0.20260917GHC2024
Validates a database, removing unusable units from it (this includes removing units that the user has explicitly ignored.) Our general strategy:
Remove all broken units (dangling dependencies)
Remove all units that are cyclic
Apply ignore flags
Remove all units which have deps with mismatching ABIs
A unusable unit module origin
UnusableUnituuUnit :: !UnitUnusable unit
uuReason :: !UnusableUnitReasonReason
uuIsReexport :: !BoolIs the "module" a reexport?
The reason why a unit is unusable.
IgnoredWithFlagWe ignored it explicitly using -ignore-package.
BrokenDependencies [UnitId]This unit transitively depends on a unit that was never present in any of the provided databases.
CyclicDependencies [UnitId]This unit transitively depends on a unit involved in a cycle. Note that the list of UnitId reports the direct dependencies of this unit that (transitively) depended on the cycle, and not the actual cycle itself (which we report separately at high verbosity.)
IgnoredDependencies [UnitId]This unit transitively depends on a unit which was ignored.
ShadowedDependencies [UnitId]This unit transitively depends on a unit which was shadowed by an ABI-incompatible unit.
Outputable UnusableUnitReasonDefined in ghc-10.0.0.20260917 · GHC.Unit.External.ValidateLike selectPackages, but doesn't return a list of unmatched
packages. Furthermore, any packages it returns are *renamed*
if the UnitArg has a renaming associated with it.
Outputable UnitErrDefined in ghc-10.0.0.20260917 · GHC.Unit.External.ValidateTakes a list of UnitIds (and their "parent" dependency, used for error messages), and returns the list with dependencies included, in reverse dependency order (a units appears before those it depends on).
Similar to closeUnitDeps but takes a list of already loaded units as an additional argument.