arch-hs-diff showed wrong flags

[berberman]

$ arch-hs-diff skylighting-core 0.8.5 0.10
  ▶ You didn't pass -f, different flag values may make difference in dependency resolving.
  ⓘ Loading community.db...
  ⓘ Start running...
  ⓘ Downloading cabal file from https://hackage.haskell.org/package/skylighting-core-0.8.5/revision/0.cabal...
  ⓘ Downloading cabal file from https://hackage.haskell.org/package/skylighting-core-0.10/revision/0.cabal...
Package: skylighting-core
Version: 0.8.5  ⇒  0.10
Synopsis: syntax highlighting library
URL: https://github.com/jgm/skylighting
Depends:
    containers  -any
    regex-pcre-builtin  >=0.95
    aeson  >=1.0
    ansi-terminal  >=0.7
    attoparsec  -any
    base  >=4.8 && <5.0
    base64-bytestring  -any
    binary  -any
    blaze-html  >=0.5
    bytestring  -any
    case-insensitive  -any
    colour  >=2.0
    directory  >=1.2.5
    filepath  -any
    hxt  -any
    mtl  -any
    safe  -any
    text  -any
    transformers  -any
    utf8-string  -any
--------------------------------------
    containers  >=0.5.8.2
    aeson  >=1.0
    ansi-terminal  >=0.7
    attoparsec  -any
    base  >=4.8 && <5.0
    base64-bytestring  -any
    binary  -any
    blaze-html  >=0.5
    bytestring  -any
    case-insensitive  -any
    colour  >=2.0
    directory  >=1.2.5
    filepath  -any
    hxt  -any
    mtl  -any
    safe  -any
    text  -any
    transformers  -any
    utf8-string  -any

"regex-pcre-builtin" is required to be in range (>=0.95), but [community] does not provide this package.

MakeDepends:
    Diff  -any
    HUnit  -any
    QuickCheck  -any
    directory  -any
    pretty-show  -any
    random  -any
    tasty  -any
    tasty-golden  -any
    tasty-hunit  -any
    tasty-quickcheck  -any
--------------------------------------
    containers  -any
    Diff  -any
    HUnit  -any
    QuickCheck  -any
    directory  -any
    pretty-show  -any
    random  -any
    tasty  -any
    tasty-golden  -any
    tasty-hunit  -any
    tasty-quickcheck  -any


Flags:
  skylighting-core
    ⚐ executable:
      description:
        Build skylighting-extract tool
      default: False
      isManual: False
    ⚐ system-pcre:
      description:
        Use regex-pcre instead of regex-pcre-builtin
      default: False
      isManual: False


  ✔ Success!

Flag system-pcre is no longer available in the newer version.