.stack-work/ is a work directory used by the `stack` build tool.
The `stack` build tool has recently been gaining a lot of traction in
the Haskell community. It is very similar to the `cabal` build tool,
which also has entries in this Haskell .gitignore file.
The file name was incorrect, so it was having no effect. Also, the sandbox environment that this was supposed to be ignoring is deprecated. Probably best to just drop it entirely.
The Stackage project provides a cabal.config which locks in a specific
package set. This file should be shared between developers project so
that everyone is developing using the same versions of packages.
