do not fail on warning

.travis.yml

@@ -0,0 +1,40 @@
+# This is the simple Travis configuration, which is intended for use
+# on applications which do not require cross-platform and
+# multiple-GHC-version support. For more information and other
+# options, see:
+#
+# https://docs.haskellstack.org/en/stable/travis_ci/
+#
+# Copy these contents into the root directory of your Github project in a file
+# named .travis.yml
+
+# Choose a build environment
+dist: xenial
+
+# Do not choose a language; we provide our own build tools.
+language: generic
+
+# Caching so the next build will be fast too.
+cache:
+  directories:
+  - $HOME/.stack
+
+# Ensure necessary system libraries are present
+addons:
+  apt:
+    packages:
+      - libgmp-dev
+
+before_install:
+# Download and unpack the stack executable
+- mkdir -p ~/.local/bin
+- export PATH=$HOME/.local/bin:$PATH
+- travis_retry curl -L https://get.haskellstack.org/stable/linux-x86_64.tar.gz | tar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'
+
+install:
+# Build dependencies
+- stack --no-terminal --install-ghc test --only-dependencies
+
+script:
+# Build the package, its tests, and its docs and run the tests
+- stack --no-terminal test --haddock --no-haddock-deps

package.yaml

@@ -21,7 +21,6 @@ description:         Please see the README on GitHub at <https://github.com/jlam
 
 ghc-options:
 - -Wall
-- -Werror
 
 dependencies:
 - base >= 4.7 && < 5

subfix.cabal

@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: ba775360fd43dcdbf4bd590f4ac7b236109f33b1dabbda11cde0436d35d1399f
+-- hash: b41ddefa80def277ca2c1c6b04f8b656de59824a18abac5d5385b1f25f2a643e
 
 name:           subfix
 version:        0.1.0
@@ -35,7 +35,7 @@ library
       Paths_subfix
   hs-source-dirs:
       src
-  ghc-options: -Wall -Werror
+  ghc-options: -Wall
   build-depends:
       base >=4.7 && <5
     , transformers >=0.5.6.2 && <0.6
@@ -47,7 +47,7 @@ executable subfix
       Paths_subfix
   hs-source-dirs:
       app
-  ghc-options: -Wall -Werror -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
     , subfix
@@ -68,7 +68,7 @@ test-suite subfix-test
       Paths_subfix
   hs-source-dirs:
       test
-  ghc-options: -Wall -Werror -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -Wall -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
     , hspec >=2.7.4 && <2.8