Building on Windows
It currently does not seem possible to build qtah on Windows, or at least I haven't found any information on how to get it to build properly.
I get the following when running stack build in a Windows 10 virtual machine:
... Configuring qtah-generator-0.4.0... .\qtah-listener-gen: rawSystem: invalid argument (Exec format error)
This is caused by treating a bash script (qtah-listener-gen) as an executable on Windows, which does not seem to work, even though bash is available (as demonstrated below). https://gitlab.com/khumba/qtah/blob/master/qtah-generator/Setup.hs#L100
Replacing the lines 92-100 with (and importing System.Process):
_ <- system $ "bash " ++ genPath ++ " --gen-hs-dir ." return ()
Allows qtah-generator to configure as stack uses MSYS on Windows, but the solution is sub-optimal and I don't know Cabal well enough to propose a better solution.
qtah-cpp has the same issue: https://gitlab.com/khumba/qtah/blob/master/qtah-cpp/Setup.hs#L131
Another solution may be to replace qtah-listener-gen with a proper cross-platform Haskell program, rather than using a bash script to generate the listeners.