git-annex/doc/bugs/build_failure_on_macOS_10.14.6.mdwn

### Please describe the problem.


Working to update the macOS Homebrew Formula for git-annex 7.20191009 and I'm receiving a build error using the Homebrew build system to build via ghc 8.6.5 on macOS 10.14.6:

[[!format sh """
[ 70 of 624] Compiling Utility.Shell    ( Utility/Shell.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Utility/Shell.o )
[ 71 of 624] Compiling Git.Types        ( Git/Types.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Git/Types.o )
[ 72 of 624] Compiling Utility.FileSystemEncoding ( Utility/FileSystemEncoding.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Utility/FileSystemEncoding.o )
[ 73 of 624] Compiling Utility.Base64   ( Utility/Base64.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Utility/Base64.o )
[ 74 of 624] Compiling Utility.Aeson    ( Utility/Aeson.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Utility/Aeson.o )
[ 75 of 624] Compiling Types.Messages   ( Types/Messages.hs, dist/dist-sandbox-11319d3/build/git-annex/git-annex-tmp/Types/Messages.o )
[ 76 of 624] Compiling Database.Handle  ( Database/Handle.hs, dist/dist-sandbox-b74b6b12/build/git-annex/git-annex-tmp/Database/Handle.o )

Database/Handle.hs:273:28: error:
    • Could not deduce (BackendCompatible SqlBackend backend)
        arising from a use of ‘close'’
      from the context: (IsPersistBackend backend,
                         BaseBackend backend ~ SqlBackend)
        bound by the type signature for:
                   closeRobustly :: forall backend.
                                    (IsPersistBackend backend, BaseBackend backend ~ SqlBackend) =>
                                    backend -> IO ()
        at Database/Handle.hs:(260,1)-(263,16)
    • In the second argument of ‘($)’, namely ‘close' conn’
      In a stmt of a 'do' block: r <- try $ close' conn
      In the expression:
        do r <- try $ close' conn
           case r of
             Right () -> return ()
             Left ex@(Sqlite.SqliteException {Sqlite.seError = e})
               | e == Sqlite.ErrorBusy -> do ...
               | otherwise -> rethrow "while closing database connection" ex
    |
273 |                 r <- try $ close' conn
    |                            ^^^^^^^^^^^
cabal: Leaving directory '.'
cabal: Error: some packages failed to install:
git-annex-7.20191009-KZnzbjdUc2rE3oBBwl75Ho failed during the building phase.
The exception was:
ExitFailure 1
"""]]

Is this an artifact of ghc 8.6.5 vs 8.8.1?

### What steps will reproduce the problem?

Updated the Homebrew Formula with the appropriate changes.

[[!format sh """
# brew install ghc@8.6
# brew install --verbose --build-bottle git-annex`
"""]]

### What version of git-annex are you using? On what operating system?

git-annex 7.20191009
macOS 10.14.6
The Glorious Glasgow Haskell Compilation System, version 8.6.5

### Please provide any additional information below.

[[!format sh """
# If you can, paste a complete transcript of the problem occurring here.
# If the problem is with the git-annex assistant, paste in .git/annex/daemon.log


# End of transcript or log.
"""]]

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

git-annex has been awesome for managing a massive collection of raw images and video clips across several storage targets and editing systems.

> [[fixed|done]] --[[Joey]]