diff --git a/Cabal/Cabal.cabal b/Cabal/Cabal.cabal
index 68b96e17da3..f70ae3ce5ee 100644
--- a/Cabal/Cabal.cabal
+++ b/Cabal/Cabal.cabal
@@ -666,6 +666,9 @@ test-suite unit-tests
   ghc-options: -Wall
   default-language: Haskell2010
 
+  if !impl(ghc >= 7.10)
+    build-depends: void
+
   -- Cabal-quickcheck
   hs-source-dirs: Cabal-quickcheck/src
   other-modules:
@@ -693,9 +696,6 @@ test-suite parser-tests
   if !impl(ghc >= 8.0)
     build-depends: semigroups
 
-  if !impl(ghc >= 7.10)
-    build-depends: void
-
   if impl(ghc >= 7.8)
     build-depends:
       tree-diff      >= 0.1 && <0.2
diff --git a/Cabal/Distribution/Utils/CharSet.hs b/Cabal/Distribution/Utils/CharSet.hs
index b77bbfd21a7..b047995bb55 100644
--- a/Cabal/Distribution/Utils/CharSet.hs
+++ b/Cabal/Distribution/Utils/CharSet.hs
@@ -214,293 +214,17 @@ normalise' = CS . IM.fromList . go where
 -- Alpha Numeric character list
 -------------------------------------------------------------------------------
 
--- |
---
--- >>> size alpha
--- 102725
+-- Computing this takes some time,
+-- but they are not used in-non testing in Cabal's normal operation.
+
+-- | Note: this set varies depending on @base@ version.
 --
 alpha :: CharSet
-alpha = CS $ IM.fromList
-    [(65,90), (97,122), (170,170), (181,181), (186,186), (192,214),
-     (216,246), (248,705), (710,721), (736,740), (748,748), (750,750),
-     (880,884), (886,887), (890,893), (895,895), (902,902), (904,906),
-     (908,908), (910,929), (931,1013), (1015,1153), (1162,1327),
-     (1329,1366), (1369,1369), (1377,1415), (1488,1514), (1520,1522),
-     (1568,1610), (1646,1647), (1649,1747), (1749,1749), (1765,1766),
-     (1774,1775), (1786,1788), (1791,1791), (1808,1808), (1810,1839),
-     (1869,1957), (1969,1969), (1994,2026), (2036,2037), (2042,2042),
-     (2048,2069), (2074,2074), (2084,2084), (2088,2088), (2112,2136),
-     (2208,2226), (2308,2361), (2365,2365), (2384,2384), (2392,2401),
-     (2417,2432), (2437,2444), (2447,2448), (2451,2472), (2474,2480),
-     (2482,2482), (2486,2489), (2493,2493), (2510,2510), (2524,2525),
-     (2527,2529), (2544,2545), (2565,2570), (2575,2576), (2579,2600),
-     (2602,2608), (2610,2611), (2613,2614), (2616,2617), (2649,2652),
-     (2654,2654), (2674,2676), (2693,2701), (2703,2705), (2707,2728),
-     (2730,2736), (2738,2739), (2741,2745), (2749,2749), (2768,2768),
-     (2784,2785), (2821,2828), (2831,2832), (2835,2856), (2858,2864),
-     (2866,2867), (2869,2873), (2877,2877), (2908,2909), (2911,2913),
-     (2929,2929), (2947,2947), (2949,2954), (2958,2960), (2962,2965),
-     (2969,2970), (2972,2972), (2974,2975), (2979,2980), (2984,2986),
-     (2990,3001), (3024,3024), (3077,3084), (3086,3088), (3090,3112),
-     (3114,3129), (3133,3133), (3160,3161), (3168,3169), (3205,3212),
-     (3214,3216), (3218,3240), (3242,3251), (3253,3257), (3261,3261),
-     (3294,3294), (3296,3297), (3313,3314), (3333,3340), (3342,3344),
-     (3346,3386), (3389,3389), (3406,3406), (3424,3425), (3450,3455),
-     (3461,3478), (3482,3505), (3507,3515), (3517,3517), (3520,3526),
-     (3585,3632), (3634,3635), (3648,3654), (3713,3714), (3716,3716),
-     (3719,3720), (3722,3722), (3725,3725), (3732,3735), (3737,3743),
-     (3745,3747), (3749,3749), (3751,3751), (3754,3755), (3757,3760),
-     (3762,3763), (3773,3773), (3776,3780), (3782,3782), (3804,3807),
-     (3840,3840), (3904,3911), (3913,3948), (3976,3980), (4096,4138),
-     (4159,4159), (4176,4181), (4186,4189), (4193,4193), (4197,4198),
-     (4206,4208), (4213,4225), (4238,4238), (4256,4293), (4295,4295),
-     (4301,4301), (4304,4346), (4348,4680), (4682,4685), (4688,4694),
-     (4696,4696), (4698,4701), (4704,4744), (4746,4749), (4752,4784),
-     (4786,4789), (4792,4798), (4800,4800), (4802,4805), (4808,4822),
-     (4824,4880), (4882,4885), (4888,4954), (4992,5007), (5024,5108),
-     (5121,5740), (5743,5759), (5761,5786), (5792,5866), (5873,5880),
-     (5888,5900), (5902,5905), (5920,5937), (5952,5969), (5984,5996),
-     (5998,6000), (6016,6067), (6103,6103), (6108,6108), (6176,6263),
-     (6272,6312), (6314,6314), (6320,6389), (6400,6430), (6480,6509),
-     (6512,6516), (6528,6571), (6593,6599), (6656,6678), (6688,6740),
-     (6823,6823), (6917,6963), (6981,6987), (7043,7072), (7086,7087),
-     (7098,7141), (7168,7203), (7245,7247), (7258,7293), (7401,7404),
-     (7406,7409), (7413,7414), (7424,7615), (7680,7957), (7960,7965),
-     (7968,8005), (8008,8013), (8016,8023), (8025,8025), (8027,8027),
-     (8029,8029), (8031,8061), (8064,8116), (8118,8124), (8126,8126),
-     (8130,8132), (8134,8140), (8144,8147), (8150,8155), (8160,8172),
-     (8178,8180), (8182,8188), (8305,8305), (8319,8319), (8336,8348),
-     (8450,8450), (8455,8455), (8458,8467), (8469,8469), (8473,8477),
-     (8484,8484), (8486,8486), (8488,8488), (8490,8493), (8495,8505),
-     (8508,8511), (8517,8521), (8526,8526), (8579,8580), (11264,11310),
-     (11312,11358), (11360,11492), (11499,11502), (11506,11507),
-     (11520,11557), (11559,11559), (11565,11565), (11568,11623),
-     (11631,11631), (11648,11670), (11680,11686), (11688,11694),
-     (11696,11702), (11704,11710), (11712,11718), (11720,11726),
-     (11728,11734), (11736,11742), (11823,11823), (12293,12294),
-     (12337,12341), (12347,12348), (12353,12438), (12445,12447),
-     (12449,12538), (12540,12543), (12549,12589), (12593,12686),
-     (12704,12730), (12784,12799), (13312,19893), (19968,40908),
-     (40960,42124), (42192,42237), (42240,42508), (42512,42527),
-     (42538,42539), (42560,42606), (42623,42653), (42656,42725),
-     (42775,42783), (42786,42888), (42891,42894), (42896,42925),
-     (42928,42929), (42999,43009), (43011,43013), (43015,43018),
-     (43020,43042), (43072,43123), (43138,43187), (43250,43255),
-     (43259,43259), (43274,43301), (43312,43334), (43360,43388),
-     (43396,43442), (43471,43471), (43488,43492), (43494,43503),
-     (43514,43518), (43520,43560), (43584,43586), (43588,43595),
-     (43616,43638), (43642,43642), (43646,43695), (43697,43697),
-     (43701,43702), (43705,43709), (43712,43712), (43714,43714),
-     (43739,43741), (43744,43754), (43762,43764), (43777,43782),
-     (43785,43790), (43793,43798), (43808,43814), (43816,43822),
-     (43824,43866), (43868,43871), (43876,43877), (43968,44002),
-     (44032,55203), (55216,55238), (55243,55291), (63744,64109),
-     (64112,64217), (64256,64262), (64275,64279), (64285,64285),
-     (64287,64296), (64298,64310), (64312,64316), (64318,64318),
-     (64320,64321), (64323,64324), (64326,64433), (64467,64829),
-     (64848,64911), (64914,64967), (65008,65019), (65136,65140),
-     (65142,65276), (65313,65338), (65345,65370), (65382,65470),
-     (65474,65479), (65482,65487), (65490,65495), (65498,65500),
-     (65536,65547), (65549,65574), (65576,65594), (65596,65597),
-     (65599,65613), (65616,65629), (65664,65786), (66176,66204),
-     (66208,66256), (66304,66335), (66352,66368), (66370,66377),
-     (66384,66421), (66432,66461), (66464,66499), (66504,66511),
-     (66560,66717), (66816,66855), (66864,66915), (67072,67382),
-     (67392,67413), (67424,67431), (67584,67589), (67592,67592),
-     (67594,67637), (67639,67640), (67644,67644), (67647,67669),
-     (67680,67702), (67712,67742), (67840,67861), (67872,67897),
-     (67968,68023), (68030,68031), (68096,68096), (68112,68115),
-     (68117,68119), (68121,68147), (68192,68220), (68224,68252),
-     (68288,68295), (68297,68324), (68352,68405), (68416,68437),
-     (68448,68466), (68480,68497), (68608,68680), (69635,69687),
-     (69763,69807), (69840,69864), (69891,69926), (69968,70002),
-     (70006,70006), (70019,70066), (70081,70084), (70106,70106),
-     (70144,70161), (70163,70187), (70320,70366), (70405,70412),
-     (70415,70416), (70419,70440), (70442,70448), (70450,70451),
-     (70453,70457), (70461,70461), (70493,70497), (70784,70831),
-     (70852,70853), (70855,70855), (71040,71086), (71168,71215),
-     (71236,71236), (71296,71338), (71840,71903), (71935,71935),
-     (72384,72440), (73728,74648), (77824,78894), (92160,92728),
-     (92736,92766), (92880,92909), (92928,92975), (92992,92995),
-     (93027,93047), (93053,93071), (93952,94020), (94032,94032),
-     (94099,94111), (110592,110593), (113664,113770), (113776,113788),
-     (113792,113800), (113808,113817), (119808,119892), (119894,119964),
-     (119966,119967), (119970,119970), (119973,119974), (119977,119980),
-     (119982,119993), (119995,119995), (119997,120003), (120005,120069),
-     (120071,120074), (120077,120084), (120086,120092), (120094,120121),
-     (120123,120126), (120128,120132), (120134,120134), (120138,120144),
-     (120146,120485), (120488,120512), (120514,120538), (120540,120570),
-     (120572,120596), (120598,120628), (120630,120654), (120656,120686),
-     (120688,120712), (120714,120744), (120746,120770), (120772,120779),
-     (124928,125124), (126464,126467), (126469,126495), (126497,126498),
-     (126500,126500), (126503,126503), (126505,126514), (126516,126519),
-     (126521,126521), (126523,126523), (126530,126530), (126535,126535),
-     (126537,126537), (126539,126539), (126541,126543), (126545,126546),
-     (126548,126548), (126551,126551), (126553,126553), (126555,126555),
-     (126557,126557), (126559,126559), (126561,126562), (126564,126564),
-     (126567,126570), (126572,126578), (126580,126583), (126585,126588),
-     (126590,126590), (126592,126601), (126603,126619), (126625,126627),
-     (126629,126633), (126635,126651), (131072,173782), (173824,177972),
-     (177984,178205), (194560,195101)]
-
--- |
---
--- >>> size alphanum
--- 105901
+alpha = foldl' (flip insert) empty [ c | c <- [ minBound .. maxBound ], isAlpha c ]
+{-# NOINLINE alpha #-}
+
+-- | Note: this set varies depending on @base@ version.
 --
-{-# NOINLINE alphanum #-}
 alphanum :: CharSet
--- Note: to pretty print use
---
--- :m *Distribution.Utils.CharSet
--- :m +Text.PrettyPrint
---
--- let xs = foldl' (flip insert) Distribution.Utils.CharSet.empty [ c | c <- [ minBound .. maxBound ], isAlphaNum c ]
--- brackets $ fsep $ punctuate comma [ parens (int x Prelude.<> comma Prelude.<> int y) | (x,y) <- IM.toList $ unCS xs ]
-
-alphanum = CS $ IM.fromList
-    [(48,57), (65,90), (97,122), (170,170), (178,179), (181,181),
-     (185,186), (188,190), (192,214), (216,246), (248,705), (710,721),
-     (736,740), (748,748), (750,750), (768,884), (886,887), (890,893),
-     (895,895), (902,902), (904,906), (908,908), (910,929), (931,1013),
-     (1015,1153), (1155,1327), (1329,1366), (1369,1369), (1377,1415),
-     (1425,1469), (1471,1471), (1473,1474), (1476,1477), (1479,1479),
-     (1488,1514), (1520,1522), (1552,1562), (1568,1641), (1646,1747),
-     (1749,1756), (1759,1768), (1770,1788), (1791,1791), (1808,1866),
-     (1869,1969), (1984,2037), (2042,2042), (2048,2093), (2112,2139),
-     (2208,2226), (2276,2403), (2406,2415), (2417,2435), (2437,2444),
-     (2447,2448), (2451,2472), (2474,2480), (2482,2482), (2486,2489),
-     (2492,2500), (2503,2504), (2507,2510), (2519,2519), (2524,2525),
-     (2527,2531), (2534,2545), (2548,2553), (2561,2563), (2565,2570),
-     (2575,2576), (2579,2600), (2602,2608), (2610,2611), (2613,2614),
-     (2616,2617), (2620,2620), (2622,2626), (2631,2632), (2635,2637),
-     (2641,2641), (2649,2652), (2654,2654), (2662,2677), (2689,2691),
-     (2693,2701), (2703,2705), (2707,2728), (2730,2736), (2738,2739),
-     (2741,2745), (2748,2757), (2759,2761), (2763,2765), (2768,2768),
-     (2784,2787), (2790,2799), (2817,2819), (2821,2828), (2831,2832),
-     (2835,2856), (2858,2864), (2866,2867), (2869,2873), (2876,2884),
-     (2887,2888), (2891,2893), (2902,2903), (2908,2909), (2911,2915),
-     (2918,2927), (2929,2935), (2946,2947), (2949,2954), (2958,2960),
-     (2962,2965), (2969,2970), (2972,2972), (2974,2975), (2979,2980),
-     (2984,2986), (2990,3001), (3006,3010), (3014,3016), (3018,3021),
-     (3024,3024), (3031,3031), (3046,3058), (3072,3075), (3077,3084),
-     (3086,3088), (3090,3112), (3114,3129), (3133,3140), (3142,3144),
-     (3146,3149), (3157,3158), (3160,3161), (3168,3171), (3174,3183),
-     (3192,3198), (3201,3203), (3205,3212), (3214,3216), (3218,3240),
-     (3242,3251), (3253,3257), (3260,3268), (3270,3272), (3274,3277),
-     (3285,3286), (3294,3294), (3296,3299), (3302,3311), (3313,3314),
-     (3329,3331), (3333,3340), (3342,3344), (3346,3386), (3389,3396),
-     (3398,3400), (3402,3406), (3415,3415), (3424,3427), (3430,3445),
-     (3450,3455), (3458,3459), (3461,3478), (3482,3505), (3507,3515),
-     (3517,3517), (3520,3526), (3530,3530), (3535,3540), (3542,3542),
-     (3544,3551), (3558,3567), (3570,3571), (3585,3642), (3648,3662),
-     (3664,3673), (3713,3714), (3716,3716), (3719,3720), (3722,3722),
-     (3725,3725), (3732,3735), (3737,3743), (3745,3747), (3749,3749),
-     (3751,3751), (3754,3755), (3757,3769), (3771,3773), (3776,3780),
-     (3782,3782), (3784,3789), (3792,3801), (3804,3807), (3840,3840),
-     (3864,3865), (3872,3891), (3893,3893), (3895,3895), (3897,3897),
-     (3902,3911), (3913,3948), (3953,3972), (3974,3991), (3993,4028),
-     (4038,4038), (4096,4169), (4176,4253), (4256,4293), (4295,4295),
-     (4301,4301), (4304,4346), (4348,4680), (4682,4685), (4688,4694),
-     (4696,4696), (4698,4701), (4704,4744), (4746,4749), (4752,4784),
-     (4786,4789), (4792,4798), (4800,4800), (4802,4805), (4808,4822),
-     (4824,4880), (4882,4885), (4888,4954), (4957,4959), (4969,4988),
-     (4992,5007), (5024,5108), (5121,5740), (5743,5759), (5761,5786),
-     (5792,5866), (5870,5880), (5888,5900), (5902,5908), (5920,5940),
-     (5952,5971), (5984,5996), (5998,6000), (6002,6003), (6016,6099),
-     (6103,6103), (6108,6109), (6112,6121), (6128,6137), (6155,6157),
-     (6160,6169), (6176,6263), (6272,6314), (6320,6389), (6400,6430),
-     (6432,6443), (6448,6459), (6470,6509), (6512,6516), (6528,6571),
-     (6576,6601), (6608,6618), (6656,6683), (6688,6750), (6752,6780),
-     (6783,6793), (6800,6809), (6823,6823), (6832,6846), (6912,6987),
-     (6992,7001), (7019,7027), (7040,7155), (7168,7223), (7232,7241),
-     (7245,7293), (7376,7378), (7380,7414), (7416,7417), (7424,7669),
-     (7676,7957), (7960,7965), (7968,8005), (8008,8013), (8016,8023),
-     (8025,8025), (8027,8027), (8029,8029), (8031,8061), (8064,8116),
-     (8118,8124), (8126,8126), (8130,8132), (8134,8140), (8144,8147),
-     (8150,8155), (8160,8172), (8178,8180), (8182,8188), (8304,8305),
-     (8308,8313), (8319,8329), (8336,8348), (8400,8432), (8450,8450),
-     (8455,8455), (8458,8467), (8469,8469), (8473,8477), (8484,8484),
-     (8486,8486), (8488,8488), (8490,8493), (8495,8505), (8508,8511),
-     (8517,8521), (8526,8526), (8528,8585), (9312,9371), (9450,9471),
-     (10102,10131), (11264,11310), (11312,11358), (11360,11492),
-     (11499,11507), (11517,11517), (11520,11557), (11559,11559),
-     (11565,11565), (11568,11623), (11631,11631), (11647,11670),
-     (11680,11686), (11688,11694), (11696,11702), (11704,11710),
-     (11712,11718), (11720,11726), (11728,11734), (11736,11742),
-     (11744,11775), (11823,11823), (12293,12295), (12321,12335),
-     (12337,12341), (12344,12348), (12353,12438), (12441,12442),
-     (12445,12447), (12449,12538), (12540,12543), (12549,12589),
-     (12593,12686), (12690,12693), (12704,12730), (12784,12799),
-     (12832,12841), (12872,12879), (12881,12895), (12928,12937),
-     (12977,12991), (13312,19893), (19968,40908), (40960,42124),
-     (42192,42237), (42240,42508), (42512,42539), (42560,42610),
-     (42612,42621), (42623,42653), (42655,42737), (42775,42783),
-     (42786,42888), (42891,42894), (42896,42925), (42928,42929),
-     (42999,43047), (43056,43061), (43072,43123), (43136,43204),
-     (43216,43225), (43232,43255), (43259,43259), (43264,43309),
-     (43312,43347), (43360,43388), (43392,43456), (43471,43481),
-     (43488,43518), (43520,43574), (43584,43597), (43600,43609),
-     (43616,43638), (43642,43714), (43739,43741), (43744,43759),
-     (43762,43766), (43777,43782), (43785,43790), (43793,43798),
-     (43808,43814), (43816,43822), (43824,43866), (43868,43871),
-     (43876,43877), (43968,44010), (44012,44013), (44016,44025),
-     (44032,55203), (55216,55238), (55243,55291), (63744,64109),
-     (64112,64217), (64256,64262), (64275,64279), (64285,64296),
-     (64298,64310), (64312,64316), (64318,64318), (64320,64321),
-     (64323,64324), (64326,64433), (64467,64829), (64848,64911),
-     (64914,64967), (65008,65019), (65024,65039), (65056,65069),
-     (65136,65140), (65142,65276), (65296,65305), (65313,65338),
-     (65345,65370), (65382,65470), (65474,65479), (65482,65487),
-     (65490,65495), (65498,65500), (65536,65547), (65549,65574),
-     (65576,65594), (65596,65597), (65599,65613), (65616,65629),
-     (65664,65786), (65799,65843), (65856,65912), (65930,65931),
-     (66045,66045), (66176,66204), (66208,66256), (66272,66299),
-     (66304,66339), (66352,66378), (66384,66426), (66432,66461),
-     (66464,66499), (66504,66511), (66513,66517), (66560,66717),
-     (66720,66729), (66816,66855), (66864,66915), (67072,67382),
-     (67392,67413), (67424,67431), (67584,67589), (67592,67592),
-     (67594,67637), (67639,67640), (67644,67644), (67647,67669),
-     (67672,67702), (67705,67742), (67751,67759), (67840,67867),
-     (67872,67897), (67968,68023), (68030,68031), (68096,68099),
-     (68101,68102), (68108,68115), (68117,68119), (68121,68147),
-     (68152,68154), (68159,68167), (68192,68222), (68224,68255),
-     (68288,68295), (68297,68326), (68331,68335), (68352,68405),
-     (68416,68437), (68440,68466), (68472,68497), (68521,68527),
-     (68608,68680), (69216,69246), (69632,69702), (69714,69743),
-     (69759,69818), (69840,69864), (69872,69881), (69888,69940),
-     (69942,69951), (69968,70003), (70006,70006), (70016,70084),
-     (70096,70106), (70113,70132), (70144,70161), (70163,70199),
-     (70320,70378), (70384,70393), (70401,70403), (70405,70412),
-     (70415,70416), (70419,70440), (70442,70448), (70450,70451),
-     (70453,70457), (70460,70468), (70471,70472), (70475,70477),
-     (70487,70487), (70493,70499), (70502,70508), (70512,70516),
-     (70784,70853), (70855,70855), (70864,70873), (71040,71093),
-     (71096,71104), (71168,71232), (71236,71236), (71248,71257),
-     (71296,71351), (71360,71369), (71840,71922), (71935,71935),
-     (72384,72440), (73728,74648), (74752,74862), (77824,78894),
-     (92160,92728), (92736,92766), (92768,92777), (92880,92909),
-     (92912,92916), (92928,92982), (92992,92995), (93008,93017),
-     (93019,93025), (93027,93047), (93053,93071), (93952,94020),
-     (94032,94078), (94095,94111), (110592,110593), (113664,113770),
-     (113776,113788), (113792,113800), (113808,113817), (113821,113822),
-     (119141,119145), (119149,119154), (119163,119170), (119173,119179),
-     (119210,119213), (119362,119364), (119648,119665), (119808,119892),
-     (119894,119964), (119966,119967), (119970,119970), (119973,119974),
-     (119977,119980), (119982,119993), (119995,119995), (119997,120003),
-     (120005,120069), (120071,120074), (120077,120084), (120086,120092),
-     (120094,120121), (120123,120126), (120128,120132), (120134,120134),
-     (120138,120144), (120146,120485), (120488,120512), (120514,120538),
-     (120540,120570), (120572,120596), (120598,120628), (120630,120654),
-     (120656,120686), (120688,120712), (120714,120744), (120746,120770),
-     (120772,120779), (120782,120831), (124928,125124), (125127,125142),
-     (126464,126467), (126469,126495), (126497,126498), (126500,126500),
-     (126503,126503), (126505,126514), (126516,126519), (126521,126521),
-     (126523,126523), (126530,126530), (126535,126535), (126537,126537),
-     (126539,126539), (126541,126543), (126545,126546), (126548,126548),
-     (126551,126551), (126553,126553), (126555,126555), (126557,126557),
-     (126559,126559), (126561,126562), (126564,126564), (126567,126570),
-     (126572,126578), (126580,126583), (126585,126588), (126590,126590),
-     (126592,126601), (126603,126619), (126625,126627), (126629,126633),
-     (126635,126651), (127232,127244), (131072,173782), (173824,177972),
-     (177984,178205), (194560,195101), (917760,917999)]
+alphanum = foldl' (flip insert) empty [ c | c <- [ minBound .. maxBound ], isAlphaNum c ]
+{-# NOINLINE alphanum #-}
diff --git a/Cabal/tests/UnitTests/Distribution/Described.hs b/Cabal/tests/UnitTests/Distribution/Described.hs
index 76692ecd33b..27a0488b024 100644
--- a/Cabal/tests/UnitTests/Distribution/Described.hs
+++ b/Cabal/tests/UnitTests/Distribution/Described.hs
@@ -1,12 +1,12 @@
 {-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# OPTIONS_GHC -fno-warn-deprecations #-}
 module UnitTests.Distribution.Described where
 
-import Data.Maybe            (fromMaybe)
-import Data.Proxy            (Proxy (..))
-import Data.String           (fromString)
-import Data.Typeable         (Typeable, typeOf)
-import Data.Void             (Void, vacuous)
+import Distribution.Compat.Prelude.Internal
+import Prelude ()
+
+import Data.Typeable         (typeOf)
 import Test.QuickCheck       (Arbitrary (..), Gen, Property, choose, counterexample)
 import Test.Tasty            (TestTree, testGroup)
 import Test.Tasty.QuickCheck (testProperty)
diff --git a/Cabal/tests/UnitTests/Distribution/Utils/CharSet.hs b/Cabal/tests/UnitTests/Distribution/Utils/CharSet.hs
index b6a4e006be8..44efa858a01 100644
--- a/Cabal/tests/UnitTests/Distribution/Utils/CharSet.hs
+++ b/Cabal/tests/UnitTests/Distribution/Utils/CharSet.hs
@@ -5,19 +5,15 @@
 #endif
 module UnitTests.Distribution.Utils.CharSet where
 
-import Test.Tasty       (TestTree, testGroup)
-
-#ifdef HAS_TESTS
-import Test.Tasty.HUnit (testCase, (@?=))
 import Data.Char        (isAlpha, isAlphaNum)
 import Data.List        (foldl')
+import Test.Tasty       (TestTree, testGroup)
+import Test.Tasty.HUnit (testCase, (@?=))
 
 import qualified Distribution.Utils.CharSet as CS
-#endif
 
 tests :: TestTree
 tests = testGroup "Distribution.Utils.CharSet"
-#ifdef HAS_TESTS
     [ testCase "alphanum" $
         CS.alphanum @?= foldl' (flip CS.insert) CS.empty
             [ c | c <- [ minBound .. maxBound ], isAlphaNum c ]
@@ -25,8 +21,7 @@ tests = testGroup "Distribution.Utils.CharSet"
     , testCase "alpha" $
         CS.alpha @?= foldl' (flip CS.insert) CS.empty
             [ c | c <- [ minBound .. maxBound ], isAlpha c ]
+
+    , testCase "alpha is subset of alphanum" $
+        CS.union CS.alpha CS.alphanum @?= CS.alphanum
     ]
-#else
-    [
-    ]
-#endif