$ stack ghci
Configuring GHCi with the following packages: simple-ad
GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
<command line>: can't load .so/.DLL for: /Users/devon/.stack/snapshots/x86_64-osx/lts-7.2/8.0.1/lib/x86_64-osx-ghc-8.0.1/symengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk/libHSsymengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk-ghc8.0.1.dylib (dlopen(/Users/devon/.stack/snapshots/x86_64-osx/lts-7.2/8.0.1/lib/x86_64-osx-ghc-8.0.1/symengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk/libHSsymengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk-ghc8.0.1.dylib, 5): Symbol not found: _basic_free_heap
  Referenced from: /Users/devon/.stack/snapshots/x86_64-osx/lts-7.2/8.0.1/lib/x86_64-osx-ghc-8.0.1/symengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk/libHSsymengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk-ghc8.0.1.dylib
  Expected in: flat namespace
 in /Users/devon/.stack/snapshots/x86_64-osx/lts-7.2/8.0.1/lib/x86_64-osx-ghc-8.0.1/symengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk/libHSsymengine-0.1.2.0-CFDO5GoFnPYANnt609mDOk-ghc8.0.1.dylib)