stdout is:exact

stdout is a handle managing the programs standard output.
A handle managing output to the Haskell program's standard output channel.
sinkHandle applied to stdout. Subject to fusion
Stream bytes to stdout Unlike toHandle, stdout gracefully terminates on a broken output pipe.
Stream chunks of bytes to standard output The chunks are not necessarily aligned to line boundaries
Stream lines of Text to standard output
Pipes-style nomenclature for putStr.
Add the stdout produced running a test to the report for that test.
import Data.Function ((&))

writeXmlReport "report.xml"
[ passed "A passing test"
& stdout "Test ran succesfully!"
& inSuite "Test suite"
]
A sink into stdout.