[Haskell-beginners] ghc failed to compile trifecta while installing idris

[Robert Dodier]

Hi, 

I'm trying to install Idris. 

I am working on Ubuntu 14.04. ghc --version reports 7.6.3.

After installing Haskell via apt-get, I then executed cabal update,
which succeeded.

I then tried cabal install idris and it eventually failed while
trying to install trifecta.

I then tried cabal install -v3 idris and got the following info
about the trifecta problem, which I've appended to this message
as a PS.

Maybe I can patch Highlight.hs? How would I go about that?
Unpack the tar.gz, patch the file, and repack it?

For the record, I tried to follow the instructions at:
https://github.com/idris-lang/Idris-dev/wiki/Idris-on-Ubuntu
but ran into various errors, e.g., cabal install cabal-install
failed with ExitFailure 139. 

Thanks for any advice.

best,

Robert Dodier

PS. The tail end of the output of cabal install -v3 idris:

[ 8 of 13] Compiling Text.Trifecta.Highlight (
src/Text/Trifecta/Highlight.hs, dist/build/Text/Trifecta/Highlight.o )
*** Parser:
*** Renamer/typechecker:

src/Text/Trifecta/Highlight.hs:46:15:
    Ambiguous occurrence `Comment'
    It could refer to either `Text.Blaze.Internal.Comment',
                             imported from `Text.Blaze.Internal' at
src/Text/Trifecta/Highlight.hs:35:1-26
                          or `Text.Parser.Token.Highlight.Comment',
                             imported from `Text.Parser.Token.Highlight' at
src/Text/Trifecta/Highlight.hs:36:1-34
Upsweep partially successful.
*** Deleting temp files:
Deleting: /tmp/ghc13030_0/ghc13030_0.s
Warning: deleting non-existent /tmp/ghc13030_0/ghc13030_0.s
link(batch): upsweep (partially) failed OR
   Main.main not exported; not linking.
*** Deleting temp files:
Deleting: /tmp/ghc13030_0/ghc13030_0.hscpp
*** Deleting temp dirs:
Deleting: /tmp/ghc13030_0
/usr/bin/ghc returned ExitFailure 1
Failed to install trifecta-1.5
World file is already up to date.
cabal: Error: some packages failed to install:
idris-0.9.16 depends on trifecta-1.5 which failed to install.
trifecta-1.5 failed during the building phase. The exception was:
ExitFailure 1