_Complex type causes Unknown type kind: 100: Complex

[drbixx]

Include files that contain structs with _Complex ... fields, result in

% atlas build |& sanatize
[Info] (..) is the current workspace
  Verifying dependencies for complex_issue@0.1.0
     Info:  Dependency on futhark@any version already satisfied
  Verifying dependencies for futhark@0.13.1
     Info:  Dependency on termstyle@any version already satisfied
  Verifying dependencies for termstyle@0.1.0
     Info:  Dependency on macroutils@any version already satisfied
  Verifying dependencies for macroutils@1.2.0
     Info:  Dependency on https://github.com/PMunch/nimbleutils@>= 0.3.0 already satisfied
  Verifying dependencies for nimbleutils@0.3.1
   Building complex_issue/complex_issue using c backend
project/_deps/futhark/src/futhark.nim(49, 7) Warning: Couldn't find futhark version from 'nimble dump project/_deps/futhark/futhark.nimble' [User]
Unknown type kind: 100: Complex
stack trace: (most recent call last)
project/_deps/futhark/src/futhark.nim(881, 19) importcImpl
project/_deps/futhark/src/futhark.nim(254, 34) addUsings
project/_deps/futhark/src/futhark.nim(229, 10) findAlias
project/src/complex_issue.nim(13, 1) template/generic instantiation of `importc` from here
project/_deps/futhark/src/futhark.nim(689, 14) template/generic instantiation of `importcImpl` from here
project/_deps/futhark/src/futhark.nim(229, 10) Error: Unknown kind in findAlias: {"kind":"invalid","value":"???"}
       Tip: 10 messages have been suppressed, use --verbose to show them.
nimble.nim(304)          buildFromDir

    Error:  Build failed for the package: complex_issue

Ideally, _Complex types are supported. At minimum, it would be nice if the error can be turned into a warning, especially when the nim bindings for _Complex types aren't needed.

complex_issue.txt