title: How to get cabal and nix work together
body: <p>As far as I understood, <strong>Nix</strong> is alternative for <strong>cabal sandbox</strong>.
  I finally managed to install Nix, but I still don't understand how it can replace a sandbox.</p>
  
  <p>I understand you don't need cabal using Nix and the wrapped version of GHC; however if you want
  to publish a package you'll need at some point to package it using cabal. Therefore, you need to be able to write and test your cabal configuration within NIX. How do you do that?</p>
  
  <p>Ideally, I would like an environment similar to cabal sandbox but "contained" within NIX, is that possible? In fact, what I really would like is the equivalent of nested sandboxes — as I usually work on projects made of multiple packages.</p>
  
  <h1>Update about my current workflow</h1>
  
  <p>At the moment I work on 2 or 3 independent projects (P1, P2, P3) which are each composed of 2 or 3 cabal modules/packages, let's say for P1: L11, L12 (libraries)
   and E11 (executables). E11 depends on L12 which depends on L11. I mainly split the executables from the library because they are private and kept on a private git repo.</p>
  
  <p>In theory, each project could have this own sandbox (shared between its submodules). I tried that (having a common sandbox for L11 L12 and E11), but it's quickly annoying because, if you modify L11, you can't rebuild it because E11 depends on it, so I have to uninstall E11 first to recompile L11.
  It might be no exactly the case, but I encounter the similar problem.
  This would be fine if I were occasionally modifying L11, but in practice, I changed it more that E11.</p>
  
  <p>As the shared sandbox doesn't work, so I went back to the one sandbox for every package solution. It's working but is less than ideal. 
  The main problem is if I modify L11, I need to compile it twice (once in L11, and then again in E11). Also, each time I'm starting a new sandbox, as everybody knows, I need to wait a while to get everything package downloaded and recompiled.</p>
  
  <p>So by using Nix, I'm hopping to be able to set up separate cabal "environments" per project, which solves all the issue aboves.</p>
  
  <p>Hope this is clearer.</p>