Resolving dependencies...
Downloading concurrent-extra-0.7.0.9...
[1 of 1] Compiling Main             ( /tmp/concurrent-extra-0.7.0.9-16189/concurrent-extra-0.7.0.9/dist/dist-sandbox-1428821d/setup/setup.hs, /tmp/concurrent-extra-0.7.0.9-16189/concurrent-extra-0.7.0.9/dist/dist-sandbox-1428821d/setup/Main.o )
Linking /tmp/concurrent-extra-0.7.0.9-16189/concurrent-extra-0.7.0.9/dist/dist-sandbox-1428821d/setup/setup ...
Configuring concurrent-extra-0.7.0.9...
Building concurrent-extra-0.7.0.9...
Preprocessing library concurrent-extra-0.7.0.9...

Control/Concurrent/Broadcast.hs:80:8:
    Could not find module ‘Control.Concurrent.Timeout’
    There are files missing in the ‘unbounded-delays-0.1.0.8’ package,
    try running 'ghc-pkg check'.
    Use -v to see a list of the files searched for.
Failed to install concurrent-extra-0.7.0.9
cabal: Error: some packages failed to install:
concurrent-extra-0.7.0.9 failed during the building phase. The exception was:
ExitFailure 1