MueLu: Complex build broken
*Created by: mhoemmen*
@trilinos/muelu
https://github.com/trilinos/Trilinos/issues/2426#issuecomment-457394324
https://testing-vm.sandia.gov/cdash/viewBuildError.php?buildid=4453539
```
In file included from /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/parameterlist/src/Teuchos_ParameterEntry.hpp:52:0,
from /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/parameterlist/src/Teuchos_ParameterList.hpp:51,
from /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/parameterlist/src/Teuchos_XMLParameterListCoreHelpers.hpp:51,
from /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/comm/src/Teuchos_XMLParameterListHelpers.hpp:51,
from /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/muelu/test/scaling/Driver.cpp:51:
/scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/core/src/Teuchos_RCP.hpp:
In instantiation of ‘Teuchos::RCP<T>::RCP(const Teuchos::RCP<T2>&) [with T2 = Xpetra::MultiVector<>; T = Xpetra::MultiVector<std::complex<double>, int, int, Kokkos::Compat::KokkosDeviceWrapperNode<Kokkos::Serial> >]’:
/scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/muelu/test/scaling/Driver.cpp:472:100:
required from ‘int main_(Teuchos::CommandLineProcessor&, Xpetra::UnderlyingLib&, int, char**) [with Scalar = std::complex<double>; LocalOrdinal = int; GlobalOrdinal = int; Node = Kokkos::Compat::KokkosDeviceWrapperNode<Kokkos::Serial>]’
/scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/muelu/test/scaling/../unit_tests/MueLu_Test_ETI.hpp:153:104:
required from here /scratch/trilinos/workspace/trilinos-folder/Trilinos_pullrequest_gcc_7.2.0/Trilinos/packages/teuchos/core/src/Teuchos_RCP.hpp:289:38:
error: cannot convert ‘Xpetra::MultiVector<>*’ to ‘Xpetra::MultiVector<std::complex<double>, int, int, Kokkos::Compat::KokkosDeviceWrapperNode<Kokkos::Serial> >*’ in initialization node_(r_ptr.access_private_node())
```
[jhux2 edited error for readability]
## Motivation and Context
This blocks Sierra's Trilinos promotion.
## Related Issues
* Blocks #2426
issue