2 files changed, 66 insertions, 30 deletions

diff --git a/.travis.yml b/.travis.yml
index 618741d..f0ecd95 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,45 +1,80 @@
-# See also https://github.com/hvr/multi-ghc-travis for more information
+# This file has been generated -- see https://github.com/hvr/multi-ghc-travis
 language: c
-
 sudo: false
 
-# The following lines enable several GHC versions and/or HP versions
-# to be tested; often it's enough to test only against the last
-# release of a major GHC version. Setting HPVER implictly sets
-# GHCVER. Omit lines with versions you don't need/want testing for.
+cache:
+  directories:
+    - $HOME/.cabsnap
+    - $HOME/.cabal/packages
+
+before_cache:
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.tar
+
 matrix:
-   include:
-   - env: CABALVER=1.18 GHCVER=7.8.4 CTOPTS=""
-     addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
-   - env: CABALVER=1.22 GHCVER=7.10.1 CTOPTS="--show-details=streaming"
-     addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.1],sources: [hvr-ghc]}}
-   - env: CABALVER=head GHCVER=head CTOPTS="--show-details=streaming"
-     addons: {apt: {packages: [cabal-install-head,ghc-head], sources: [hvr-ghc]}}
+  include:
+    - env: CABALVER=1.18 GHCVER=7.8.4
+      compiler: ": #GHC 7.8.4"
+      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
+    - env: CABALVER=1.22 GHCVER=7.10.1
+      compiler: ": #GHC 7.10.1"
+      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.1], sources: [hvr-ghc]}}
 
-   allow_failures:
-      - env: CABALVER=head GHCVER=head
 
 before_install:
-   - export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
+ - unset CC
+ - export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
 
 install:
-   - cabal --version
-   - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
-   - travis_retry cabal update
-   - sed -i 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config # The container environment reports 16 cores
-   - cabal install --only-dependencies --enable-tests --enable-benchmarks
+ - cabal --version
+ - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
+ - if [ -f $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz ];
+   then
+     zcat $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz >
+          $HOME/.cabal/packages/hackage.haskell.org/00-index.tar;
+   fi
+ - travis_retry cabal update -v
+ - sed -i 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config
+ - cabal install --only-dependencies --enable-tests --enable-benchmarks --dry -v > installplan.txt
+ - sed -i -e '1,/^Resolving /d' installplan.txt; cat installplan.txt
 
-script:
-   - cabal configure --enable-tests --enable-benchmarks -v2
-   - cabal build
-
-   - cabal test $CTOPTS
+# check whether current requested install-plan matches cached package-db snapshot
+ - if diff -u installplan.txt $HOME/.cabsnap/installplan.txt;
+   then
+     echo "cabal build-cache HIT";
+     rm -rfv .ghc;
+     cp -a $HOME/.cabsnap/ghc $HOME/.ghc;
+     cp -a $HOME/.cabsnap/lib $HOME/.cabsnap/share $HOME/.cabsnap/bin $HOME/.cabal/;
+   else
+     echo "cabal build-cache MISS";
+     rm -rf $HOME/.cabsnap;
+     mkdir -p $HOME/.ghc $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin;
+     cabal install --only-dependencies --enable-tests --enable-benchmarks;
+   fi
 
-   - cabal check
+# snapshot package-db on cache miss
+ - if [ ! -d $HOME/.cabsnap ];
+   then
+      echo "snapshotting package-db to build-cache";
+      mkdir $HOME/.cabsnap;
+      cp -a $HOME/.ghc $HOME/.cabsnap/ghc;
+      cp -a $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin installplan.txt $HOME/.cabsnap/;
+   fi
 
-   - cabal sdist
+# Here starts the actual work to be performed for the package under test;
+# any command which exits with a non-zero exit code causes the build to fail.
+script:
+ - if [ -f configure.ac ]; then autoreconf -i; fi
+ - cabal configure --enable-tests --enable-benchmarks -v2  # -v2 provides useful information for debugging
+ - cabal build   # this builds all libraries and executables (including tests/benchmarks)
+ - cabal test
+ - cabal check
+ - cabal sdist   # tests that a source-distribution can be generated
 
-   - SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
-     (cd dist && cabal install --force-reinstalls "$SRC_TGZ")
+# Check that the resulting source distribution can be built & installed.
+# If there are no other `.tar.gz` files in `dist`, this can be even simpler:
+# `cabal install --force-reinstalls dist/*-*.tar.gz`
+ - SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
+   (cd dist && cabal install --force-reinstalls "$SRC_TGZ")
 
 # EOF
diff --git a/hmacaroons.cabal b/hmacaroons.cabal
index 85958b9..8c6f410 100644
--- a/hmacaroons.cabal
+++ b/hmacaroons.cabal
@@ -43,6 +43,7 @@ extra-source-files:  README.md
                      CONTRIBUTING.md
                      CHANGELOG.md
 cabal-version:       >=1.10
+tested-with:         GHC==7.8.4, GHC==7.10.1
 
 source-repository head
     type:       git