| UCL_1_0 | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| UHC | Distribution.Compiler, Distribution.Simple.Compiler, Distribution.Simple | 
| uhcProgram | Distribution.Simple.Program.Builtin, Distribution.Simple.Program | 
| unAbiHash | Distribution.Types.AbiHash, Distribution.Package, Distribution.Make, Distribution.Simple | 
| Unambiguous | Distribution.Simple.PackageIndex | 
| UnboxedSums | Language.Haskell.Extension, Distribution.Simple | 
| UnboxedTuples | Language.Haskell.Extension, Distribution.Simple | 
| unComponentId | Distribution.Types.ComponentId, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unconfigureProgram | Distribution.Simple.Program.Db | 
| uncurry | Distribution.Compat.Prelude.Internal | 
| UndecidableInstances | Language.Haskell.Extension, Distribution.Simple | 
| UndecidableSuperClasses | Language.Haskell.Extension, Distribution.Simple | 
| undefined | Distribution.Compat.Prelude.Internal | 
| unDefUnitId | Distribution.Types.UnitId, Distribution.Backpack, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unexpected | Distribution.Compat.Parsing, Distribution.Compat.CharParsing | 
| unFlagAssignment | Distribution.Types.Flag, Distribution.PackageDescription | 
| unFlagName | Distribution.Types.Flag, Distribution.PackageDescription | 
| unfoldr | Distribution.Compat.Prelude.Internal | 
| unfoldrM | Distribution.Utils.Generic | 
| UnicodeSyntax | Language.Haskell.Extension, Distribution.Simple | 
| Unicode_DFS_2015 | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| Unicode_DFS_2016 | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| Unicode_TOU | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| unifiedIPIDRequired | Distribution.Simple.Compiler, Distribution.Simple | 
| unintersperse | Distribution.Utils.Generic, Distribution.Simple.Utils | 
| union | Distribution.Simple.Program.Hpc | 
| unionLeft | Distribution.Compat.Graph | 
| unionRight | Distribution.Compat.Graph | 
| unionVersionIntervals | Distribution.Types.VersionInterval, Distribution.Version, Distribution.Simple | 
| UnionVersionRanges | Distribution.Types.VersionRange.Internal | 
| unionVersionRanges | Distribution.Types.VersionRange.Internal, Distribution.Types.VersionRange, Distribution.Version, Distribution.Simple | 
| UnionVersionRangesF | Distribution.Types.VersionRange.Internal, Distribution.Types.VersionRange, Distribution.Version, Distribution.Simple | 
| uniqueField | Distribution.FieldGrammar.Class, Distribution.FieldGrammar | 
| uniqueFieldAla | Distribution.FieldGrammar.Class, Distribution.FieldGrammar | 
| UnitId | Distribution.Types.UnitId, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unitIdSupported | Distribution.Simple.Compiler, Distribution.Simple | 
| unitIdTarget | Distribution.Types.LocalBuildInfo | 
| unitIdTarget' | Distribution.Types.LocalBuildInfo | 
| Universal_FOSS_exception_1_0 | Distribution.SPDX.LicenseExceptionId, Distribution.SPDX | 
| unknownCompilerInfo | Distribution.Compiler, Distribution.Simple.Compiler, Distribution.Simple | 
| UnknownExtension | Language.Haskell.Extension, Distribution.Simple | 
| UnknownLanguage | Language.Haskell.Extension, Distribution.Simple | 
| UnknownLicense | Distribution.License, Distribution.Make, Distribution.Simple | 
| unless | Distribution.Compat.Prelude.Internal | 
| unLex | Distribution.Fields.LexerMonad | 
| Unlicense | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| UnliftedFFITypes | Language.Haskell.Extension, Distribution.Simple | 
| UnliftedNewtypes | Language.Haskell.Extension, Distribution.Simple | 
| unlines | Distribution.Compat.Prelude.Internal | 
| unlit | Distribution.Simple.PreProcess.Unlit | 
| unpack | Distribution.Compat.Newtype | 
| unpack' | Distribution.Compat.Newtype | 
| unPackageName | Distribution.Types.PackageName, Distribution.Package, Distribution.PackageDescription, Distribution.Make, Distribution.Simple | 
| unPackageNameST | Distribution.Types.PackageName, Distribution.Package, Distribution.PackageDescription, Distribution.Make, Distribution.Simple | 
| unPkgconfigName | Distribution.Types.PkgconfigName, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unPP | Distribution.Parsec | 
| UnqualComponentName | Distribution.Types.UnqualComponentName, Distribution.PackageDescription | 
| unqualComponentNameToPackageName | Distribution.Types.UnqualComponentName, Distribution.PackageDescription | 
| unregHook | Distribution.Simple.UserHooks, Distribution.Simple | 
| unregister |  | 
| 1 (Function) | Distribution.Simple.Program.HcPkg | 
| 2 (Function) | Distribution.Simple.Register | 
| unregisterCommand | Distribution.Simple.Setup | 
| unregisterInvocation | Distribution.Simple.Program.HcPkg | 
| Unsafe | Language.Haskell.Extension, Distribution.Simple | 
| unsafeFromUTF8BS | Distribution.Utils.ShortText | 
| unsafeMkDefUnitId | Distribution.Types.UnitId, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unsnoc | Distribution.Utils.Generic | 
| unsnocNE | Distribution.Utils.Generic | 
| UnspecifiedLicense | Distribution.License, Distribution.Make, Distribution.Simple | 
| unsupportedExtensions | Distribution.Simple.Compiler, Distribution.Simple | 
| unsupportedLanguages | Distribution.Simple.Compiler, Distribution.Simple | 
| until | Distribution.Compat.Prelude.Internal | 
| unUnitId | Distribution.Types.UnitId, Distribution.Package, Distribution.Make, Distribution.Simple | 
| unUnqualComponentName | Distribution.Types.UnqualComponentName, Distribution.PackageDescription | 
| unUnqualComponentNameST | Distribution.Types.UnqualComponentName, Distribution.PackageDescription | 
| unvalidateBenchmark | Distribution.PackageDescription.FieldGrammar | 
| unvalidateTestSuite | Distribution.PackageDescription.FieldGrammar | 
| unwords | Distribution.Compat.Prelude.Internal | 
| unzip | Distribution.Compat.Prelude.Internal | 
| unzip3 | Distribution.Compat.Prelude.Internal | 
| updatePackageDescription | Distribution.Types.PackageDescription, Distribution.PackageDescription | 
| updateProgram | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| UPL_1_0 | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| upper | Distribution.Compat.CharParsing | 
| UpperBound |  | 
| 1 (Type/Class) | Distribution.Types.VersionInterval, Distribution.Version, Distribution.Simple | 
| 2 (Data Constructor) | Distribution.Types.VersionInterval, Distribution.Version, Distribution.Simple | 
| usageAlternatives | Distribution.Simple.Command | 
| usageDefault | Distribution.Simple.Command | 
| use | Distribution.Compat.Lens | 
| usedExtensions | Distribution.Types.BuildInfo, Distribution.PackageDescription | 
| userBug | Distribution.PackageDescription.Utils | 
| UserBuildTarget | Distribution.Simple.BuildTarget | 
| UserBuildTargetProblem | Distribution.Simple.BuildTarget | 
| UserBuildTargetUnrecognised | Distribution.Simple.BuildTarget | 
| userError | Distribution.Compat.Prelude.Internal | 
| UserHooks |  | 
| 1 (Type/Class) | Distribution.Simple.UserHooks, Distribution.Simple | 
| 2 (Data Constructor) | Distribution.Simple.UserHooks, Distribution.Simple | 
| userMaybeSpecifyPath | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| UserPackageDB | Distribution.Simple.Compiler, Distribution.Simple | 
| UserSpecified | Distribution.Simple.Program.Types, Distribution.Simple.Program | 
| userSpecifiedArgs | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| userSpecifyArgs | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| userSpecifyArgss | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| userSpecifyPath | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| userSpecifyPaths | Distribution.Simple.Program.Db, Distribution.Simple.Program | 
| usesTemplateHaskellOrQQ | Distribution.Types.BuildInfo, Distribution.PackageDescription | 
| U_boot_exception_2_0 | Distribution.SPDX.LicenseExceptionId, Distribution.SPDX |