# cabal sandbox init Writing a default package environment file to /sandbox-ghc-pkg.dist/cabal.sandbox.config Creating a new sandbox at /sandbox-ghc-pkg.dist/sandbox # cabal exec cabal: The program 'my-executable' is required but it could not be found. # cabal install Resolving dependencies... Configuring my-0.1... Preprocessing executable 'my-executable' for my-0.1.. Building executable 'my-executable' for my-0.1.. Preprocessing library for my-0.1.. Building library for my-0.1.. Installing executable my-executable in Installing library in Installed my-0.1 # cabal exec