Resolving dependencies...
Configuring darcs-beta-2.2.98.4...
Failed to install darcs-beta-2.2.98.4
Build log ( /home/builder/.cabal/logs/darcs-beta-2.2.98.4.log ):
cabal: Entering directory '/tmp/cabal-tmp-20697/darcs-beta-2.2.98.4'
cabal: Leaving directory '/tmp/cabal-tmp-20697/darcs-beta-2.2.98.4'
cabal: Error: some packages failed to install:
darcs-beta-2.2.98.4 failed during the configure step. The exception was:
user error ('/opt/ghc/8.0.2/bin/ghc' exited with an error:

/tmp/cabal-tmp-20697/darcs-beta-2.2.98.4/Distribution/ShellHarness.hs:19:1:
error:
Failed to load interface for ‘Control.OldException’
Perhaps you meant Control.Exception (from base-4.9.0.0)
Use -v to see a list of the files searched for.
)