Re: [Haskell-beginners] Using "cabal test" and getting "cabal: Prelude.read: no parse"

I don't call the `read' function in my source code anywhere. I do derive `read' instances in my data definitions, but otherwise grep finds no occurrences. I'm fairly certain this is a bug in the testing framework, but I don't know how to debug it further. The cabal compilation process seems to produce a file at "dist/build/MY_PACKAGE_NAME-testsStub/MY_PACKAGE_NAME-testsStub-tmp/MY_PACKAGE_NAME-testsStub.hs". This file contains: module Main ( main ) where import Distribution.Simple.Test ( stubMain ) import Tests ( tests ) main :: IO () main = stubMain tests In the parent directory there is an executable, "dist/build/MY_PACKAGE_NAME-testsStub/MY_PACKAGE_NAME-testsStub" which appears to be the file which cabal executes when I call "cabal test". I'm not sure how this executable is created but I suspect it comes from the file I quoted above. I'm beginning to suspect that the testing framework is not playing well with something. This is my test file: http://lpaste.net/104680 I'm using the detailed-0.9 "type" of test module, because the detailed-1.0 "type" isn't present on my system. Is this the problem? They seem to reference detailed-1.0 in this user guide I found for Cabal: http://www.haskell.org/cabal/release/rc/doc/users-guide/#test-suites . Though now, seeing the URL, it seems that the user guide might be for a release candidate version of cabal? I found that page through googling how to set up a test suite in Cabal. Can someone point me at a different guide or tutorial? I tried this (http://www.haskell.org/cabal/users-guide/) guide as well, but it doesn't give any examples and barely references test suites at all. On Mon, May 26, 2014 at 5:20 PM, Erik Price wrote:

It's possible that you're calling the

read :: Read a => String -> a

function somewhere with a parameter that the function doesn't know how to parse. I ran into this just today when I called

read "a string" :: String

when what I needed to call was

read "\"a string\"" :: String

e

On Monday, May 26, 2014, Boris wrote:

...

Hello,

Last time I got such an error, it was because I was using 'read' for a type I had defined myself, deriving Read, but on something that was not reelated to the type. For instance:

data Foo = Foo deriving (Read, Show)

x :: Foo x = read "Bar"

Do you use read somwhere?

HTH

Daniel King writes:

...

Hi all,

I created a cabal project with the attached cabal file. I run:

cabal configure --enable-tests cabal build cabal test

and then I get the error:

cabal: Prelude.read: no parse

I'm not sure how to debug this any further. If I execute:

./dist/build/scientific-pl-testsStub/scientific-pl-testsStub

with any input I've tried (numbers, array notation, string notation, etc.) and I get that same error.

I can post the whole project if that is helpful.

Thanks for the debugging tips!

The full log is:

danking@spock # cabal configure --enable-tests Resolving dependencies... Configuring scientific-pl-0.1.0.0... danking@spock # cabal build Building scientific-pl-0.1.0.0... Preprocessing test suite 'scientific-pl-tests' for scientific-pl-0.1.0.0... [1 of 3] Compiling SPLData ( SPLData.hs, dist/build/SPLData.o ) [2 of 3] Compiling SPLEval ( SPLEval.hs, dist/build/SPLEval.o ) [3 of 3] Compiling Tests ( tests/Tests.hs, dist/build/Tests.o ) In-place registering scientific-pl-tests-0.1.0.0... [1 of 1] Compiling Main (

dist/build/scientific-pl-testsStub/scientific-pl-testsStub-tmp/scientific-pl-testsStub.hs, dist/build/scientific-pl-testsStub/scientific-pl-testsStub-tmp/Main.o ) Linking dist/build/scientific-pl-testsStub/scientific-pl-testsStub ... Preprocessing executable 'scientific-pl' for scientific-pl-0.1.0.0... [1 of 3] Compiling SPLData ( SPLData.hs, dist/build/scientific-pl/scientific-pl-tmp/SPLData.o ) [2 of 3] Compiling SPLEval ( SPLEval.hs, dist/build/scientific-pl/scientific-pl-tmp/SPLEval.o ) [3 of 3] Compiling Main ( Main.hs, dist/build/scientific-pl/scientific-pl-tmp/Main.o ) Linking dist/build/scientific-pl/scientific-pl ... danking@spock # cabal test Running 1 test suites... Test suite scientific-pl-tests: RUNNING... cabal: Prelude.read: no parse 1 danking@spock #

-- Boris Daix _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

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-- Dan King