Source: h5py Followup-For: Bug #1020054 The problem is partially related to the -L/usr/lib/x86_64-linux-gnu -lhdf5 in the failing compilation line.
Since debian provides serial and mpi builds of hdf5, there is no /usr/lib/x86_64-linux-gnu/libhdf5.so (there is libhdf5_serial.so and libhdf5_openmpi.so instead). h5py should be accessing flags using pkgconfig, which would provide the more specific path -L/usr/lib/x86_64-linux-gnu/hdf5/openmpi -lhdf5 In any case, for some reason ld is finding /usr/lib/x86_64-linux-gnu/hdf5/openmpi/libhdf5.a instead of /usr/lib/x86_64-linux-gnu/hdf5/openmpi/libhdf5.so The problem may be in the configuration of h5pcc, which has -shlib and -noshlib flags. Apparently it currently defaults to static build (-noshlib): $ h5pcc --showconfig gcc -I/usr/include/hdf5/openmpi -L/usr/lib/x86_64-linux-gnu/hdf5/openmpi /usr/lib/x86_64-linux-gnu/hdf5/openmpi/libhdf5_hl.a /usr/lib/x86_64-linux-gnu/hdf5/openmpi/libhdf5.a -lcrypto -lcurl -lsz -lz -ldl -lm -Wl,-rpath -Wl,/usr/lib/x86_64-linux-gnu/hdf5/openmpi -I/usr/lib/x86_64-linux-gnu/openmpi/include -I/usr/lib/x86_64-linux-gnu/openmpi/include/openmpi -L/usr/lib/x86_64-linux-gnu/openmpi/lib -lmpi i.e. h5pcc links to libhdf5.a The shlib configuration would be $ h5pcc --showconfig -shlib gcc -I/usr/include/hdf5/openmpi -L/usr/lib/x86_64-linux-gnu/hdf5/openmpi -lhdf5_hl -lhdf5 -lcrypto -lcurl -lsz -lz -ldl -lm -Wl,-rpath -Wl,/usr/lib/x86_64-linux-gnu/hdf5/openmpi So it looks like h5py now needs to be more explicit specifying -shlib or -noshlib. Again, I can't see why this behaviour would have changed. It doesn't sound like a change that would be caused by gcc-12.
