Configure output does not match config.log

[rennehan]

Hi, I noticed a mismatch between the ./configure output and the config.log output, relating to the HDF5 library.

I'm using HDF5(+MPI) 1.8.22 without specifying --with-hdf5 in the ./configure command. Configure finds the correct library with no issues, and the configure information gives:

HDF5 enabled : yes
- parallel : yes

During my run, I noticed that the snapshot time steps were taking ages. It turns out, config.log says that:

HDF5_Type='serial'

That is odd, so I reconfigured by passing --with-hdf5=which h5pcc and that successfully made the two outputs match. I thought this was a bit misleading and should probably match. I'm not sure if the issue is reproducible or not at this time.

[pwdraper]

Hi @rennehan, this is the correct behaviour. The configure script just checks for an HDF5 initially (using h5cc), so that will report as a serial version, further checks then determine if the HDF5 library also supports MPI, at which time we change to parallel.

The result of all this is that the macro HAVE_PARALLEL_HDF5 will be defined or not. Check your config.h file
and see if this is working correctly without specifying the need to use h5pcc. If that doesn't help, can you attach the config.log file from the build you think is broken I can check to see what happened.