Resolving dependencies...
Configuring canonical-json-0.5.0.0...
Building canonical-json-0.5.0.0...
Failed to install canonical-json-0.5.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.4.3/canonical-json-0.5.0.0-C55mX6svFDC1PZo9FshGzt.log ):
cabal: Entering directory '/tmp/cabal-tmp-17457/canonical-json-0.5.0.0'
Configuring canonical-json-0.5.0.0...
Preprocessing library for canonical-json-0.5.0.0..
Building library for canonical-json-0.5.0.0..
[1 of 4] Compiling Text.JSON.Canonical.Types ( Text/JSON/Canonical/Types.hs, dist/build/Text/JSON/Canonical/Types.o )
[2 of 4] Compiling Text.JSON.Canonical.Parse ( Text/JSON/Canonical/Parse.hs, dist/build/Text/JSON/Canonical/Parse.o )

Text/JSON/Canonical/Parse.hs:260:29: error:
    Ambiguous occurrence ‘<>’
    It could refer to either ‘Prelude.<>’,
                             imported from ‘Prelude’ at Text/JSON/Canonical/Parse.hs:16:8-32
                             (and originally defined in ‘GHC.Base’)
                          or ‘Doc.<>’,
                             imported from ‘Text.PrettyPrint’ at Text/JSON/Canonical/Parse.hs:28:1-37
                             (and originally defined in ‘Text.PrettyPrint.HughesPJ’)
    |
260 | jchar '"'   = Doc.char '\\' <> Doc.char '"'
    |                             ^^

Text/JSON/Canonical/Parse.hs:261:29: error:
    Ambiguous occurrence ‘<>’
    It could refer to either ‘Prelude.<>’,
                             imported from ‘Prelude’ at Text/JSON/Canonical/Parse.hs:16:8-32
                             (and originally defined in ‘GHC.Base’)
                          or ‘Doc.<>’,
                             imported from ‘Text.PrettyPrint’ at Text/JSON/Canonical/Parse.hs:28:1-37
                             (and originally defined in ‘Text.PrettyPrint.HughesPJ’)
    |
261 | jchar '\\'  = Doc.char '\\' <> Doc.char '\\'
    |                             ^^

Text/JSON/Canonical/Parse.hs:270:41: error:
    Ambiguous occurrence ‘<>’
    It could refer to either ‘Prelude.<>’,
                             imported from ‘Prelude’ at Text/JSON/Canonical/Parse.hs:16:8-32
                             (and originally defined in ‘GHC.Base’)
                          or ‘Doc.<>’,
                             imported from ‘Text.PrettyPrint’ at Text/JSON/Canonical/Parse.hs:28:1-37
                             (and originally defined in ‘Text.PrettyPrint.HughesPJ’)
    |
270 |         . map (\(k,v) -> sep [jstring k <> colon, nest 2 (jvalue v)])
    |                                         ^^

Text/JSON/Canonical/Parse.hs:284:30: error:
    Ambiguous occurrence ‘<>’
    It could refer to either ‘Prelude.<>’,
                             imported from ‘Prelude’ at Text/JSON/Canonical/Parse.hs:16:8-32
                             (and originally defined in ‘GHC.Base’)
                          or ‘Doc.<>’,
                             imported from ‘Text.PrettyPrint’ at Text/JSON/Canonical/Parse.hs:28:1-37
                             (and originally defined in ‘Text.PrettyPrint.HughesPJ’)
    |
284 | punctuate' l _ r []     = [l <> r]
    |                              ^^
cabal: Leaving directory '/tmp/cabal-tmp-17457/canonical-json-0.5.0.0'
cabal: Error: some packages failed to install:
canonical-json-0.5.0.0-C55mX6svFDC1PZo9FshGzt failed during the building
phase. The exception was:
ExitFailure 1