48 lines
2 KiB
Text
48 lines
2 KiB
Text
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### Please describe the problem.
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### What steps will reproduce the problem?
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Build git-annex with GHC 8.6.
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### What version of git-annex are you using? On what operating system?
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7.20181211, master
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### Please provide any additional information below.
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Following the implementation plan for the [MonadFail Proposal](https://wiki.haskell.org/MonadFail_Proposal), GHC 8.6 has enabled `-XMonadFailDesugaring` by default.
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Some of the code in git-annex uses failable patterns in `do`-blocks, so it fails to compile starting from GHC 8.6, as there is no `MonadFail` instance for `Annex`. Here is an example of such an error:
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Remote/Glacier.hs:165:17: error:
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• No instance for (Control.Monad.Fail.MonadFail Annex)
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arising from a do statement
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with the failable pattern ‘(_, Just h, _, pid)’
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• In a stmt of a 'do' block:
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(_, Just h, _, pid) <- liftIO $ createProcess cmd
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In the expression:
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do let cmd = ...
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(_, Just h, _, pid) <- liftIO $ createProcess cmd
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ok <- ifM
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(liftIO $ hIsEOF h)
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(return False, sink =<< liftIO (L.hGetContents h))
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liftIO $ hClose h
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....
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In an equation for ‘go’:
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go (Just e)
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= do let cmd = ...
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(_, Just h, _, pid) <- liftIO $ createProcess cmd
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ok <- ifM
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(liftIO $ hIsEOF h)
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(return False, sink =<< liftIO (L.hGetContents h))
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....
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165 | (_, Just h, _, pid) <- liftIO $ createProcess cmd
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| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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### 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)
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Just trying to start using it. I have built it with `-XNoMonadFailDesugaring` for now.
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