Hi Peter,
I was not aware of that script, thanks for the pointer. multi-ghc-travis is more high level as it generates the travis config using the cabal file's tested-with field, something that was on my todo list. My script is a shell script to be invoked from a travis/appveyor.yml config. It can potentially be used in place of the shell snippets generated by multi-ghc-travis. So I can compare the shell part of the two, some differences that I can see on a quick look:
* package-test is more general, it works for windows as well
* It can be run easily on your local machine as well which is convenient for debugging any failures or if you just want to test on local machine instead of travis.
* It supports cabal as well as stack for testing
* It tests from source distribution to make sure the generated source dist is not broken
* It has a simple knob to send coverage info to
coveralls.io
-harendra