"Pattern match failure in do expression at libraries\Win32\System\Win32\Types.hsc:311:9-15" about win32 HOT 5 CLOSED

Hmm that looks like a program or configuration error. You've somehow ended up in withHandleToHANDLEPosix that's a program bug. Posix handles aren't defined in WinIO.

Since temporary does not have a dependency on Win32 the issue must be in one of it's dependencies. It looks like something is either calling withHandleToHANDLEPosix or is calling withHandleToHANDLE on a version of Win32 without WinIO support.

from win32.

It's depending on base: https://gitlab.haskell.org/ghc/ghc/-/blob/3d5cb3352c1e1c20f0d5de427f4edbc765ce06d6/libraries/base/System/IO.hs#L500

from win32.

I do not follow. Base doesn't call into Win32 to create handles. It has its own routines to do so.

The code in base handles the IO manager switch itself

findTempName = findTempNamePosix <!> findTempNameWinIO

And does not enter the posix code. If it did the compiler wouldn't bootstrap and nothing using WinIO would work.

from win32.

Turns out it is a Win32 bug, a typo has caused the CPP macro to go missing in the one place that wouldn't cause a build failure.

I'll do some backport tomorrow to make a 2.10.0.1 which cabal should be able to use for a fix.

from win32.

nice find

from win32.