Stack ide does not work when target project requires ghc 7.8

[CRogers]

This gist has the minimal failing stack project. Note it is using lts-2.14. Changing to lts-3.0 fixes this problem.

$ stack --version
Version 0.1.3.1

I'm using stack-ide commit fda52a9. I'm using OS X.

$ stack ide start
{"tag":"ResponseWelcome","contents":[0,1,1]}
{"tag":"ResponseLog","contents":"[Info] Initializing ide-backend session @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:195:3)\n"}
{"tag":"ResponseLog","contents":"[Debug] Session dir = /Users/callumr/Dropbox/Programming/atom/atom-stack-ide/haskell/test-data/no-compile-errors/session.68905 @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:208:3)\n"}
{"tag":"ResponseLog","contents":"[Debug] Dist dir = /Users/callumr/Dropbox/Programming/atom/atom-stack-ide/haskell/test-data/no-compile-errors/.stack-work/dist/x86_64-osx/Cabal-1.18.1.5/ @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:210:3)\n"}
{"tag":"ResponseLog","contents":"[Debug] Local working dir = /Users/callumr/Dropbox/Programming/atom/atom-stack-ide/haskell/test-data/no-compile-errors/ @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:217:17)\n"}
{"tag":"ResponseLog","contents":"[Info] Searching for ide-backend-server on this path: /Users/callumr/Dropbox/Programming/atom/atom-stack-ide/haskell/test-data/no-compile-errors/.stack-work/install/x86_64-osx/lts-2.14/7.8.4/bin/:/Users/callumr/.stack/snapshots/x86_64-osx/lts-2.14/7.8.4/bin/:/Users/callumr/.nix-profile/bin:/Users/callumr/.nix-profile/sbin:/Users/callumr/.cabal/bin/:/Users/callumr/.local/share/trails/bin/unix/:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/:/Users/callumr/.local/bin/:/Users/callumr/.cabal/bin:/Users/callumr/.cabal/bin:/Applications/ghc-7.10.1.app/Contents/bin:/usr/local/bin/:/Users/callumr/bin/:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.RPC.Client ./IdeSession/RPC/Client.hs:341:5)\n"}
{"tag":"ResponseLog","contents":"[Info] Found ide-backend-server - using this one: /Users/callumr/.local/bin/ide-backend-server @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.RPC.Client ./IdeSession/RPC/Client.hs:343:5)\n"}
{"tag":"ResponseLog","contents":"[Debug] Recompile required, starting... @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update.ExecuteSessionUpdate ./IdeSession/Update/ExecuteSessionUpdate.hs:223:5)\n"}
{"tag":"ResponseLog","contents":"[Info] Restarting session due to server dieing: External exception: ghc-7.10.2: readCreateProcess: runInteractiveProcess: exec: does not exist (No such file or directory). Local exception: user error (IdeSession.RPC.Stream ended, causing not enough bytes) @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:428:7)\n"}
{"tag":"ResponseUpdateSession","contents":{"tag":"UpdateStatusCrashRestart","contents":"External exception: ghc-7.10.2: readCreateProcess: runInteractiveProcess: exec: does not exist (No such file or directory). Local exception: user error (IdeSession.RPC.Stream ended, causing not enough bytes)"}}
{"tag":"ResponseLog","contents":"[Info] Restarting ide-backend-server @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update ./IdeSession/Update.hs:351:3)\n"}
{"tag":"ResponseLog","contents":"[Info] Searching for ide-backend-server on this path: /Users/callumr/Dropbox/Programming/atom/atom-stack-ide/haskell/test-data/no-compile-errors/.stack-work/install/x86_64-osx/lts-2.14/7.8.4/bin/:/Users/callumr/.stack/snapshots/x86_64-osx/lts-2.14/7.8.4/bin/:/Users/callumr/.nix-profile/bin:/Users/callumr/.nix-profile/sbin:/Users/callumr/.cabal/bin/:/Users/callumr/.local/share/trails/bin/unix/:/Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/:/Users/callumr/.local/bin/:/Users/callumr/.cabal/bin:/Users/callumr/.cabal/bin:/Applications/ghc-7.10.1.app/Contents/bin:/usr/local/bin/:/Users/callumr/bin/:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.RPC.Client ./IdeSession/RPC/Client.hs:341:5)\n"}
{"tag":"ResponseLog","contents":"[Info] Found ide-backend-server - using this one: /Users/callumr/.local/bin/ide-backend-server @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.RPC.Client ./IdeSession/RPC/Client.hs:343:5)\n"}
{"tag":"ResponseLog","contents":"[Debug] Recompile required, starting... @(ideba_HqZKAqZV4wa5sqhSD7XjZv:IdeSession.Update.ExecuteSessionUpdate ./IdeSession/Update/ExecuteSessionUpdate.hs:223:5)\n"}

Then, after a RequestGetSourceErrors:

{"tag":"RequestGetSourceErrors","contents":[]}
{"tag":"ResponseGetSourceErrors","contents":[{"errorSpan":{"tag":"TextSpan","contents":"<<server died>>"},"errorKind":"KindServerDied","errorMsg":"ghc-7.10.2: readCreateProcess: runInteractiveProcess: exec: does not exist (No such file or directory)"}]}