Disable simd flag for bitvec

Author: fendor

cabal.project

@@ -76,7 +76,12 @@ constraints:
   happy == 1.20.1.1,
   filepath installed,
   -- for ghc 8.10, stm-hamt 1.2.0.10 doesn't build
-  stm-hamt < 1.2.0.10
+  stm-hamt < 1.2.0.10,
+  -- Centos 7 comes with an old gcc version that doesn't know about
+  -- the flag '-fopen-simd', which blocked the release 2.2.0.0.
+  -- We want to be able to benefit from the performance optimisations
+  -- in the future, thus: TODO: remove this flag.
+  bitvec -simd
 
 -- This is benign and won't affect our ability to release to Hackage,
 -- because we only depend on `ekg-json` when a non-default flag