@adamjstewart
```
think you'll find that if you try running something like:
spack spec libsplash ^hdf5@1.8.15
It will complain that libsplash does not depend on hdf5.
This is a bug in Spack's dependency resolution. A workaround
for this is to tell it to always depend on hdf5.
```
@davydden
```
to expand on @adamjstewart comment, spack will make a union
of dependencies,
i.e. hdf5@1.8.6: + hdf5+mpi = hdf5:1.8.6:+mpi, that's why it works.
```
thank you for the hint!
Adds a package for
[libSplash](https://github.com/ComputationalRadiationPhysics/libSplash),
a high-level library around serial and parallel HDF5 for regular
grids and particle data sets.
```
libSplash aims at developing a HDF5-based I/O library for HPC
simulations. It is created as an easy-to-use frontend for the
standard HDF5 library with support for MPI processes in a cluster
environment. While the standard HDF5 library provides detailed
low-level control, libSplash simplifies tasks commonly found in
large-scale HPC simulations, such as iter- ative computations
and MPI distributed processes.
```
libSplash is a dependency for [PIConGPU](http://picongpu.hzdr.de),
an open-source, many-core, fully-relativistic particle-in-cell
code and further software developed at
[Helmholz-Zentrum Dresden - Rossendorf](https://www.hzdr.de).
libSplash builds in two versions, one without MPI writing
domain-decomposed posix-style HDF5 files per process and one
(default) with MPI and MPI-I/O ("parallel HDF5") support
aggregating into a single file per MPI communicator.
libSplash is used in conjunction with
[openPMD](http://openPMD.org), see also
[github.com/openPMD/](https://github.com/openPMD/).
