Hi!

While rebuilding the python related packages against the Python 3.15rc2
version I ran into the adios4dolfinx FTBFS [1], which is reported in
#1145118.

After looking into this, I found that the problem is due to the fact
that with HDF5 version 2, we need to pass an extra flag to enable
parallel (HDF5_PREFER_PARALLEL). So, I've added that in debian/rules,
for the MPI variant.

Additionally, the HDF5_ROOT:PATH variable is different when using the
serial variant or the MPI variant, and the FindHDF5 CMake module doesn't
find it, so I've also added those settings to debian/rules.

I've applied these changes in the sandbox [2] to verify that adios2
builds successfully, and then rebuilt adios4dolfinx against it, which
also built successfully.

Setting the severity as serious, as this misconfiguration triggers a
FTBFS in a different package.

Happy hacking,

[1]: https://buildd.debian.org/status/fetch.php?pkg=adios4dolfinx&arch=all&ver=0.11.0-2&stamp=1789226652&raw=0
[2]: https://debusine.debian.net/debian/r-python-python3.15/

We believe that the bug you reported is fixed in the latest version of
adios2, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1147536@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Francesco Ballarin <ballarin@debian.org> (supplier of updated adios2 package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sun, 13 Sep 2026 04:56:26 +0000
Source: adios2
Architecture: source
Version: 2.12.1+dfsg1-3
Distribution: unstable
Urgency: medium
Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>
Changed-By: Francesco Ballarin <ballarin@debian.org>
Closes: 1147536
Changes:
 adios2 (2.12.1+dfsg1-3) unstable; urgency=medium
 .
   [ Maximiliano Curia ]
   * Set HDF5_PREFER_PARALLEL for the parallel build. Closes: #1147536.
   * Set the HDF5_ROOT:PATH explicitly
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 13b43cee7db8058d553de4d32e82fe3cf57404b1 29604 adios2_2.12.1+dfsg1-3.debian.tar.xz
 98e7c38b75876939cead70cd650d781f2feba610 12717 adios2_2.12.1+dfsg1-3_source.buildinfo
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 c90fcc6dd642b5affbef2b4f96c7b30f7af5f32a4df6fb819d4abf6828f05470 29604 adios2_2.12.1+dfsg1-3.debian.tar.xz
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Files:
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