[petsc-dev] CFLAGS and COPTFLAGS

[Barry Smith]

  I have no objection to someone setting up a branch to test allowing versioning (and PETSC_ARCH) with the —prefix option.

   Barry

On Jan 22, 2014, at 1:43 PM, Jed Brown <jed at jedbrown.org> wrote:

> Barry Smith <bsmith at mcs.anl.gov> writes:
> 
>> On Jan 22, 2014, at 1:24 PM, Jed Brown <jed at jedbrown.org> wrote:
>> 
>>> Barry Smith <bsmith at mcs.anl.gov> writes:
>>> 
>>>> When we first tried to follow “community standards” with —prefix I
>>>> was told that “community standards” did not recognize the need for
>>>> multiple installs and that community standards did not allow for
>>>> putting archs onto names to allow multiple installs.  We
>>>> specifically removed the concept of PETSC_ARCH for installs for this
>>>> reason. Have community standards changed?
>>> 
>>> There is a big difference between having the install variant in the path
>> 
>>   I have no idea what the sentence fragment above is suppose to mean. 
> 
> /opt/petsc/arch-dbg/
> 
> User has to manually set flags to find that path.  If we didn't set
> RPATH, they'd also need LD_LIBRARY_PATH.  (Not setting RPATH is nice for
> testing new system configurations, among other things.)
> 
>>> (user has to manage paths themselves) and versioning libraries installed
>>> to the same path.  We can continue with using the prefix for everything
>>> (which some distros will work around to avoid offloading path management
>>> to the user) or we can allow multiple installs to a standard path (users
>>> don't have to deal with paths, instead run petsc-3.5.0-dbg-config).
>> 
>>   I am not fundamentally objecting to name spacing the things
>>   installed but I previously understood that this was considered a
>>   big no-no.
> 
> Installing to funky paths is discouraged, but versioning libraries is
> encouraged.  If there is only one variant, that versioning is usually
> libfoo.so.1.2.3.  Then you can have several versions installed and
> precompiled binaries can keep using the old versions.
> 
> When there are multiple variants (e.g, python2 and python3), the
> libraries usually absorb the variant name.