Cabal sandbox complaining about reinstalls?

gistfile1.txt

cabal install --only-dependencies | grep reinstall                                                                                                                                1 ↵
unix-2.7.0.1 (reinstall) changes: bytestring-0.10.4.0 -> 0.10.2.0
directory-1.2.1.0 (reinstall)
process-1.2.0.0 (reinstall)
cabal: The following packages are likely to be broken by the reinstalls:
haskell98-2.0.0.3
ghc-7.8.3
Cabal-1.18.1.4
bin-package-db-0.0.0.0
haskeline-0.7.1.2
hpc-0.6.0.1
Use --force-reinstalls if you want to install anyway.