[ET Trac] [Einstein Toolkit] #136: Don't rebuild external libraries so often

[Einstein Toolkit]

#136: Don't rebuild external libraries so often
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  Reporter:  eschnett     |       Owner:        
      Type:  enhancement  |      Status:  review
  Priority:  minor        |   Milestone:        
 Component:  Cactus       |     Version:        
Resolution:               |    Keywords:        
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Comment (by bmundim):

 Hi Erik:

 >The patch is missing the declaration of GSL_INSTALL_DIR in the
 configuration.ccl file.
 >Or do you envision this to be a global environment variable instead of a
 Cactus
 >configuration variable?

 I thought more like an environment variable, but I am fine with declaring
 it in configuration.ccl.
 What is the advantage of doing so though? It seems to me that it serves
 only to document
 the environment or configuration variables used. Is there anything else?
 What is the idea
 or road map behind these options at configuration.ccl?

 >It's a somewhat dangerous options; e.g. we couldn't use it in our
 standard simfactory option lists, >because there is no mechanism to clean
 these external locations.

 I am not sure I understood why it is dangerous. Once you know the
 directory the external libraries
 were installed you know where to clean them. It is all in your
 GSL_INSTALL_DIR variables (or equivalent).

 >It's also dangerous because it doesn't take compiler compatibility into
 account.

 Yes, you are right about the compiler compatibility and it is the only
 problem I see
 at the moment. However, the user or simfactory option list can still use
 the default
 installation config/scratch directories. Those users that see the
 compatibility issue
 as a big problem would still be configuring the same way as before. Those
 that don't
 face this issue on a daily basis or it is happy to work around it (for
 example by
 having different external locations for different compilers) would now
 have at least
 a better alternative to do so (instead of simply moving the library away
 from its original
 installation directory).

 Again, I am not advocating to change the default, I am only proposing to
 add an option
 such that we can install libraries in directories we choose to do so.

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/136#comment:12>
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