What you describe sounds a lot like this issue:
https://github.com/commercialhaskell/stack/issues/2545
On Wed, Sep 14, 2016 at 1:26 PM David McBride
That's not what I'm observering. I intentially put -Wall and some odd code in a local copy of pipes-csv, stack clean, stack build.
/home/toad/working/pipes-csv-1.4.0/src/Pipes/Csv.hs:216:3: Warning: A do-notation statement discarded a result of type ‘String’ Suppress this warning by saying ‘_ <- getLine’ or by using the flag -fno-warn-unused-do-bind
In another project, stack clean, stack build
pipes-csv-1.4.0: configure pipes-csv-1.4.0: build pipes-csv-1.4.0: copy/register
Nothing at all.
stack.yaml is basically this, but with a few extra packages.
flags: {} packages: - '.' - '../pipes-csv-1.4.0' extra-deps: [] resolver: lts-3.1
stack --version Version 1.1.2 x86_64 hpack-0.14.0