haskell - How can I debug if resetting a cabal sandbox does not solve dependency errors? -

i have curious situation. have package used work , no apparent reason stopped running cabal test.

$ cabal test sandbox created after package configured. re-configuring used options. if fails, please run configure manually. resolving dependencies... configuring dump-0.2.6... cabal: following package dependencies requested --dependency='interpolatedstring-perl6=interpolatedstring-perl6-0.9.0-806887e26af0b5e9d9f99d13a2b9d08c' --dependency='hspec=hspec-2.1.8-4133af4aaac7344a4e3a6a8a90be2cb8' --dependency='haskell-src-meta=haskell-src-meta-0.6.0.10-044625c00cdf446dac843874b8e39126' given installed package instance not exist. 

i tried reinstall sandbox running

cabal sandbox delete cabal sandbox init cabal install 

which helps not.

then noticed text saying the sandbox created after package configured. try run

cabal configure 

after get

$ cabal test      re-configuring test suites enabled. if fails, please run configure manually. resolving dependencies... configuring dump-0.2.6... cabal: @ least following dependencies missing: hspec -any 

what might going wrong? can next step try debug this?

versions

$ echo {cabal,ghc}" --version;" | sh cabal-install version 1.22.2.0 using version 1.22.2.0 of cabal library  glorious glasgow haskell compilation system, version 7.10.1 

to cabal install install dependencies of tests must use --enable-tests options. (for packages install don't plan run tests, , installing dependencies of tests potentially waste of time.) based on error messages in post guess must use cabal configure --enable-tests in order use cabal test; i'm not sure purpose of is.