Getting "Prelude.read: no parse" error when using detailed-0.9 tests with cabal

I tried to follow this guide in order to write some tests for a Haskell package using the detailed-0.9 test type. The cabal file is

Name:           bar
Version:        1.0
License:        BSD3
Cabal-Version:  >= 1.10
Build-Type:     Simple

Library
    exposed-modules:     Foo
    build-depends:       base >=4.9 && <4.10
    default-language:    Haskell2010

Test-Suite test-bar
    type:       detailed-0.9
    test-module: Bar
    build-depends: base, Cabal >= 1.9.2
    default-language:    Haskell2010

and Bar.hs is

module Bar ( tests ) where

import Distribution.TestSuite

tests :: IO [Test]
tests = return [ Test succeeds, Test fails ]
  where
    succeeds = TestInstance
        { run = return $ Finished Pass
        , name = "succeeds"
        , tags = []
        , options = []
        , setOption = \_ _ -> Right succeeds
        }
    fails = TestInstance
        { run = return $ Finished $ Fail "Always fails!"
        , name = "fails"
        , tags = []
        , options = []
        , setOption = \_ _ -> Right fails
        }

However, when I run the tests with

cabal configure --enable-tests
cabal build
cabal test

I get

Preprocessing test suite 'test-bar' for bar-1.0...
[1 of 1] Compiling Main             ( dist/build/test-barStub/test-barStub-tmp/test-barStub.hs, dist/build/test-barStub/test-barStub-tmp/Main.dyn_o )
Linking dist/build/test-barStub/test-barStub ...
Running 1 test suites...
Test suite test-bar: RUNNING...
Prelude.read: no parse

This also happens with the code from this repository.

Using strace cabal test I managed to see that the last file that cabal tries to open is dist/test/cabal-test-1804289383846930886.log, which does not exist. Creating the file does not help.

Is the detailed-0.9 test type still experimental? Should I use exitcode-stdio-1.0 instead?

GHC version: 8.0.1
cabal version: 1.24.0.0