Hello,
I failed installing tree-monad. Can anyone help?
$ cabal install tree-monad
Resolving dependencies…
Build profile: -w ghc-8.8.4 -O1
In order, the following will be built (use -v for more details):
- tree-monad-0.3 (lib:tree-monad) (requires build)
Starting tree-monad-0.3 (all, legacy fallback)
Building tree-monad-0.3 (all, legacy fallback)Failed to build tree-monad-0.3.
Build log (
/home/notooth/.cabal/logs/ghc-8.8.4/tree-monad-0.3-b4bcf854e96e60a82865aa68c2ec426634c56470077fbb8284a6dcd6a86c1ad1.log
):
Configuring tree-monad-0.3…
Preprocessing library for tree-monad-0.3…
Building library for tree-monad-0.3…
[1 of 1] Compiling Control.Monad.SearchTree ( Control/Monad/SearchTree.hs, dist/build/Control/Monad/SearchTree.o )Control/Monad/SearchTree.hs:51:3: error:
‘fail’ is not a (visible) method of class ‘Monad’
|
51 | fail _ = None
| ^^^^Control/Monad/SearchTree.hs:85:3: error:
‘fail’ is not a (visible) method of class ‘Monad’
|
85 | fail _ = mzero
| ^^^^
cabal: Failed to build tree-monad-0.3. See the build log above for details.