Re: [OF signal] Compilation errors due to mpi.h

[Mike Miller]

On Fri, Feb 28, 2014 at 11:41:14 +0100, Juan Pablo Carbajal wrote:
> During installation of latest signal package there are errors due to
> mpi.h not found. I guess this is another instance of badly defined
> CPPFLAGS.

This is likely an instance of switching HDF5 libraries after building
Octave. At least that's where I've run into it before. If you build
Octave with the non-MPI HDF5 library, everything is fine. If you then
install one of the MPI-enabled HDF5 libraries, you will not be able to
build any oct-files that include HDF5 header files.

> Is there a way we can solve this problem in a consistent way?
> This involves improving configure.ac and PKG_ADD. If we can't find the
> headers in a few reasonable places then we could prompt the user. Or
> is there another way of doing this? (besides asking the user to export
> the correct CPPFLAGS, which will put off many users).

My suggestion would be to fix it in the HDF5 library ;)

This is not something that Octave Forge packages should have to deal
with, they are simply inheriting the compile flags from Octave. If the
flags don't work without changing anything, that's a bug in Octave. But
as I said above, I'm guessing you installed a new set of HDF5 libraries
which invalidates the flags you built Octave with.

My personal solution has become to always build Octave with
CPPFLAGS=-I/usr/include/mpi, regardless of which HDF5 library I have
installed at the time, and that way the include path is included for all
subsequent builds of Octave or external oct-files. This is similar to
how the Debian Octave packages are patched to accomodate any of the HDF5
libraries.

-- 
mike