Building a Library and Executable project fails with cannot satisfy -package-id <package>-inplace

[dashkal16]

When attempting to build a project with both a library and an executable module that depends on it, epm build produces this error:

<command line>: cannot satisfy -package-id epm-lib-with-exec-0.1.0.0-inplace
    (use -v for more information)

epm-lib-with-exec.cabal:

name:                epm-lib-with-exec
version:             0.1.0.0
-- synopsis:            
-- description:         
-- license:             
author:              Byron Shelden
maintainer:          bshelden@splunk.com
-- copyright:           
category:            Bug Example
build-type:          Simple
-- extra-source-files:  
cabal-version:       >=1.10

library
  -- exposed-modules:     
  -- other-modules:       
  -- other-extensions:    
  build-depends:       base >=4.8 && <4.9
  hs-source-dirs:      src
  default-language:    Haskell2010

executable exec
  main-is:             Main.hs
  hs-source-dirs:      exec-src
  build-depends:       base >=4.8 && <4.9, epm-lib-with-exec
  default-language:    Haskell2010

src/Lib.hs:

module Lib where

dummy :: a -> a
dummy a = a

src-exec/Main.hs:

module Main where

import Lib

main :: IO ()
main = putStrLn $ dummy "Hello, World"

Full output when attempting:

% epm sandbox init
Writing a default package environment file to
/home/bshelden/devel/epm-lib-with-exec/cabal.sandbox.config
Creating a new sandbox at /home/bshelden/devel/eta-cexc/.cabal-sandbox

% epm configure
Resolving dependencies...
Configuring epm-lib-with-exec-0.1.0.0...
Warning: The 'license-file' field refers to the file 'LICENSE' which does not
exist.

% epm build    
Building epm-lib-with-exec-0.1.0.0...
Preprocessing library epm-lib-with-exec-0.1.0.0...
In-place registering epm-lib-with-exec-0.1.0.0...
Preprocessing executable 'exec' for epm-lib-with-exec-0.1.0.0...
<command line>: cannot satisfy -package-id epm-lib-with-exec-0.1.0.0-inplace
    (use -v for more information)

[dashkal16]

Note that the result does not change if I remove the sandbox and try again without it.

[rahulmutt]

I was able to determine that this bug has nothing to do with epm and is a problem with eta. I have a hunch that it has to do with the inplace package database not being read. I'll post any updates.