I have one package for each day, to save time waiting for Stack to check every executable before compiling what's changed. Each package needs a separate directory tree and a separate `.cabal` file.
+To work on a project, `cd` into that project's directory.
+
Compile with
```
stack build
To profile, use
```
-stack build --executable-profiling --library-profiling -ghc-options="-fprof-auto -rtsopts" adventofcode1601
+stack build --executable-profiling --library-profiling --ghc-options="-fprof-auto -rtsopts" adventofcode1601
```
then run with
```