Bump to latest LTS and use new HLint.

.hlint.yaml

@@ -0,0 +1,37 @@
+# HLint configuration file
+# https://github.com/ndmitchell/hlint
+
+# Not considered useful hints
+- ignore: {name: "Redundant do"}
+- ignore: {name: "Use section"}
+- ignore: {name: "Use camelCase"}
+- ignore: {name: "Use list comprehension"}
+- ignore: {name: "Redundant if"}
+- ignore: {name: "Avoid lambda"}
+- ignore: {name: "Eta reduce"}
+- ignore: {name: "Use fmap"}  # specific for GHC 7.8 compat
+- ignore: {name: "Parse error"}  # we trust the compiler over HLint
+- ignore: {name: "Use =="}  # Creates infinite loops in `EQ` using expressions
+- ignore: {name: "Evaluate"}
+- ignore: {name: "Use &&&"}
+- ignore: {name: "Redundant compare"}
+
+- ignore: {name: "Use fewer imports", within: [
+  "System.Process.Read",  # Related to 'Hide post-AMP warnings' comment
+  "Stack.Exec"  # ifdef for System.Process.Read
+  ]
+}
+
+- ignore: {name: "Use fromMaybe", within: [
+    "Stack.Types.Config.explicitSetupDeps"  # Related to 'explicit pattern matching is clearer' comment
+  ]
+}
+
+# For clarity (related to do syntax)
+- ignore: {name: "Reduce duplication", within: [
+    "Network.HTTP.Download.VerifiedSpec",
+    "Stack.PackageDumpSpec",
+    "Stack.Types.StackT",
+    "Stack.Docker"
+  ]
+}

.travis.yml

@@ -120,9 +120,9 @@ script:
    set -ex
    case "$BUILD" in
      style)
-       hlint src/ --hint=HLint.hs
-       hlint src/ --cpp-define=WINDOWS=1 --hint=HLint.hs
-       hlint test/ --cpp-simple --hint=HLint.hs
+       hlint src/
+       hlint src/ --cpp-define=WINDOWS=1
+       hlint test/ --cpp-simple
        stack --system-ghc --no-terminal build --pedantic
        ;;
      stack)

CONTRIBUTING.md

@@ -64,8 +64,8 @@ quality tool.
 Note that stack contributors need not dogmatically follow the suggested hints
 but are encouraged to debate their usefulness. If you find a hint is not useful
 and detracts from readability, consider marking it in the [configuration
-file](https://github.com/commercialhaskell/stack/blob/master/HLint.hs) to
-be ignored. Please refer to the [HLint manual](https://github.com/ndmitchell/hlint#ignoring-hints)
+file](https://github.com/commercialhaskell/stack/blob/master/.hlint.yaml) to
+be ignored. Please refer to the [HLint manual](https://github.com/ndmitchell/hlint#readme)
 for configuration syntax.
 
 Quoting [@mgsloan](https://github.com/commercialhaskell/stack/pulls?utf8=%E2%9C%93&q=is%3Apr%20author%3Amgsloan):
@@ -85,8 +85,7 @@ stack install hlint
 Once installed, you can check your changes with:
 
 ```
-hlint src/ test/ --cpp-simple --hint=HLint.hs
+hlint src/ test/ --cpp-simple
 ```
 
-Where `--cpp-simple` strips `#` lines and `--hint` explicitly specifies the
-configuration file.
+Where `--cpp-simple` strips `#` lines.

src/Stack/Types/Resolver.hs

@@ -8,10 +8,8 @@
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiWayIf #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE DataKinds #-}

src/test/Stack/GhciSpec.hs

@@ -1,5 +1,4 @@
 -- {-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE OverloadedStrings #-}
 -- {-# LANGUAGE QuasiQuotes #-}
 -- {-# LANGUAGE TemplateHaskell #-}
 

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-8.22
+resolver: lts-9.0
 # docker:
 #   enable: true
 #   repo: fpco/stack-full
@@ -19,8 +19,4 @@ flags:
 extra-deps:
 - Cabal-2.0.0.2
 - mintty-0.1.1
-- text-metrics-0.3.0
-- unicode-transforms-0.3.2
-- unliftio-core-0.1.0.0
-- unliftio-0.1.0.0
 - bindings-uname-0.1