[Halld-online] gcc version for hdsys

[Elliott Wolin]

Hi Hovanes,

There is a distinction between what is supported and what is default.

I agree that at this time gcc 4.8.0 should not be the default for the 
shell initialization script.  That was just leftover from the data 
challenge, it was a minor oversight to leave it that way, indeed we 
never made a group decision to do that, and it should be changed (I 
understand you fixed it).

As you noted, installing gcc 4.8.1 in /gapps is low priority for Paul at 
the moment, and I have no problem continuing to use the compiler in 
/apps.  Similarly, for compiling readout lists I need to use a version 
of Python in /apps, and Bryan plans to address this and analogous 
concerns when we he moves to CentOS6.

There are probably other things we only have in /apps at the moment, 
eventually we have to ensure everything we need is installed locally in 
/gapps or via RPM's and the like.




On 11/20/2013 10:04 AM, Hovanes Egiyan wrote:
> Hi Elliott,
> as you pointed out, at this point it is not in /gapps area, therefore 
> it is not
> supported on the online computers. The reason why it is not there is 
> that there are
> many other things Paul is working on. If you want to use  gcc in the 
> /apps area,
> please do it, but it should not be put in the shell initialization 
> script for the
> production account.
> Hovanes.
>
>
> On 11/20/2013 09:50 AM, Elliott Wolin wrote:
>> Hi,
>>
>> The actual situation according to Kelvin is as follows:
>>
>> RedHat distributes gcc 4.4.x with RHEL6 and officially supports it.
>>
>> The Computer Center officially supports additional versions of gcc, 
>> including gcc 4.8.0.  These typically appear in /apps, but may appear 
>> in other places such as /gapps.
>>
>> Thus gcc 4.8.0 is officially supported on the online machines by the 
>> CC, and indeed most of the code I've developed requires 4.8.x (i.e. 
>> C++11).  Although not urgent, Paul and Kelvin said they'd officially 
>> install gcc 4.8.1 in /gapps at some point (gcc 4.8.1 completes 
>> language support for C++11).
>>
>> Thus my understanding is that  gcc 4.8.x is officially supported by 
>> the CC, and one can freely use it on the online cluster without much 
>> risk.
>>
>> One potential risk is that a bug shows up in gcc 4.8.x that hasn't 
>> been fixed by GNU...clearly the CC will not track it down and fix 
>> it.  But this kind of risk is common to all public domain software. 
>> Note that RedHat will fix bugs in some public domain software they 
>> distribute, so RedHat support is stronger than CC support in this 
>> regard.
>>
>>
>>
>>
>> On 11/19/2013 10:14 PM, Hovane Egiyan wrote:
>>> Hi,
>>>
>>> the version of the gcc compiler was changed some time ago announced 
>>> for all
>>> "hdsys" account in the shell initialization script to version 4.8. I
>>> restored it back to 4.4.7,
>>> the default version for RHEL6.4. Anyone who wants to build his/her
>>> online code using gcc 4.8 is
>>> welcome to do so for their code at their own risk, but the version 4.8
>>> is not officially
>>> supported on the online machines.
>>>
>>> Best,
>>>       Hovanes
>>>
>>> _______________________________________________
>>> Halld-online mailing list
>>> Halld-online at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/halld-online
>>
>

-- 

				Sincerely,
					Elliott
  

================================================================================


  Those raised in a morally relative or neutral environment will hold
		    no truths to be self-evident.
				

Elliott Wolin
Staff Physicist, Jefferson Lab
12000 Jefferson Ave
Suite 8 MS 12A1
Newport News, VA 23606
757-269-7365

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