[petsc-dev] configure using stale packages

[Balay, Satish]

On Fri, 28 Jun 2019, Jed Brown via petsc-dev wrote:

> If we configure with --download-pnetcdf (version 1.9.0), then update the
> PETSc repository to use a new version (1.11.2), then re-run ./configure
> --download-pnetcdf, we get a warning making us look like dolts:
> 
> ===============================================================================                                                                                                                
>       Warning: Using version 1.9.0 of package pnetcdf; PETSc is tested with 1.11                                                                                                               
>       Suggest using --download-pnetcdf for a compatible pnetcdf                                                                                                                                
> ===============================================================================
> 
> It looks like we have a mechanism for gitcommit versions, but not for
> normal numbered versions?

Yes. We have some overloaded functionality here wrt --download-package
for tarballs.  This is to partly support:

--download-package=URL

[where URL could be a different version - or have a different dir structure in the tarball].

And then - our desire to avoid re-download the package if its already
downloaded.  Perhaps this part can be improved by stashing the tarball
somehow that corresponds to the URL used.. [but sometimes one can use
the same tarball with a different URL]


Wrt a git repo, one can overcome this with:

--download-package=git://URL --download-package-commit=HASH

[but configure does not expect the URL to change after a clone is
created - so that part can break]

Satish

> 
> NB: There are other changes in updating pnetcdf that will bypass this
> issue today, but I wanted to raise it in case someone had a vision for
> how the logic should be organized.  It's currently spread out, and
> any attempt at a fresh download is skipped if there is a matching
> download directory:
> 
>     if not self.packageDir: self.packageDir = self.downLoad()
>