stack ghci
[1 of 2] Compiling Main             ( /root/.stack/setup-exe-src/setup-mPHDZzAJ.hs, /root/.stack/setup-exe-src/setup-mPHDZzAJ.o )

<no location info>: error:
    Warning: Couldn't figure out LLVM version!
             Make sure you have installed LLVM 3.7
ghc: could not execute: opt

Error:
--  While building simple Setup.hs using:
      /root/.stack/programs/arm-linux/ghc-8.0.2/bin/ghc -rtsopts -threaded -clear-package-db -global-package-db -hide-all-packages -package base -main-is StackSetupShim.mainOverride -package Cabal-1.24.2.0 /root/.stack/setup-exe-src/setup-mPHDZzAJ.hs /root/.stack/setup-exe-src/setup-shim-mPHDZzAJ.hs -o /root/.stack/setup-exe-cache/arm-linux/tmp-Cabal-simple_mPHDZzAJ_1.24.2.0_ghc-8.0.2