Merge pull request #18 from Rufflewind/master

Simplify script for checking tarball + fix validation error

.travis.yml

@@ -1,4 +1,5 @@
 # NB: don't set `language: haskell` here
+language: c
 
 # See also https://github.com/hvr/multi-ghc-travis for more information
 
@@ -98,13 +99,7 @@ script:
  - cabal sdist
 
  # check that the generated source-distribution can be built & installed
- - export SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz";exit}') ;
-   cd dist/;
-   if [ -f "$SRC_TGZ" ]; then
-      cabal install --force-reinstalls "$SRC_TGZ";
-   else
-      echo "expected '$SRC_TGZ' not found";
-      exit 1;
-   fi
+ - SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
+   (cd dist && cabal install --force-reinstalls "$SRC_TGZ")
 
 # EOF

README.md

@@ -89,15 +89,11 @@ script:
  - cabal check
  - cabal sdist   # tests that a source-distribution can be generated
 
-# The following scriptlet checks that the resulting source distribution can be built & installed
- - export SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz";exit}') ;
-   cd dist/;
-   if [ -f "$SRC_TGZ" ]; then
-      cabal install --force-reinstalls "$SRC_TGZ";
-   else
-      echo "expected '$SRC_TGZ' not found";
-      exit 1;
-   fi
+# 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")
 
 ```