Problem 1159

Summary:	Re-running ./Configure does not remember path to XercesC
Product:	Geant4	Reporter:	Michael Kelsey <kelsey>
Component:	config	Assignee:	Ben Morgan <Ben.Morgan>
Status:	CLOSED FIXED
Severity:	trivial
Priority:	P5
Version:	9.4
Hardware:	Apple
OS:	Mac OS X

Description Michael Kelsey 2011-01-14 00:29:21 CET

I recently installed XercesC on my system and did a clean rebuild of GEANT4 9.4.  Using |./Configure -build|, I gave it the path to the XercesC installation, and the build ran to completion successfully.

Just now, I had to redo part of the 9.4 build (I had forgotten to clean out G4UIcommon), so I ran |./Configure -build| again, picking up default answers from the previous cycle.  Everything was fine, until I hit the GDML question:

 *OPTIONS FOR GEANT4 OPTIONAL EXTENSION MODULES*
 Enable the Geometry Description Markup Language (GDML) module? [y] 
 checking for XercesC install... no

 Autodetection failed to locate XercesC in the standard locations on your system. 
 Please enter the path to your XercesC install (i.e. if XercesC is installed
 in PATH/include/xercesc, enter PATH), or type '-' to CANCEL the build of the 
 GDML module.
 XercesC path:  /usr/local/xerces
 checking for XercesC install... /usr/local/xerces

I don't know what the "standard locations" for this package are, since it doesn't not actually provide for any sort of installation procedure.  What I notice is that the script doesn't seem to record the path that I provide (/usr/local/xerces), which I think it should.

Comment 1 Michael Kelsey 2011-01-19 20:34:55 CET

I took a closer look at ./Configure, and I think I see the problem.  The shell variable which specifies the XercesC location is "g4gdml_xercesc_root" (see env.sh and config.sh), but its value isn't pre-loaded into the variables used internally in the GDML block.

It looks to me as though there should be a "preset" line at the beginning of the GDML block (line 5686 of ./Configure):

        with_xercesc_root=$g4gdml_xercesc_root

That would ensure that the "user input" and "search" variables are preloaded with the previously set value, and only if they are empty will the system actually perform the search and prompt.

I've confirmed that this change works as expected for |./Configure -de -build| (the previous value is carried over) and for |./Configure -build| without reading config.sh (the user is prompted as before).

Comment 2 Ben Morgan 2011-02-11 14:10:28 CET

This is now fixed in SVN. I had to use a slightly more involved logic than the suggested patch, which results in the following behaviour:

1) The check for XercesC proceeds as before. The 'standard locations' are common directories in which we might expect to find a XercesC install, specifically:

/usr/include 
/usr/local/include 
/opt/local/include 
/sw/include

They are 'best guesses' and we can add to them if needed.

You can optionally run Configure with

./Configure -build -Dwith_xercesc_root=/where/you/installed/xercesc

which with autoenable GDML and use the supplied path to search for Xercesc, falling over to query the user if it fails to find Xercesc in that location.


2) Re-running Configure as

./Configure -build

and choosing the default answers will pick up the last remebered value of the Xercesc installation path (it actually also rechecks it).

3) Re-running Configure as

./Configure -build -Dwith_xercesc_root=/some/other/path/to/xercesc

and choosing the default answers will in this case *override* the last remembered value for the Xercesc path (and equivalently enable and serach for Xercesc if you previously disabled it).


That may all seem rather convoluted, but I think it covers all the cases - at least it gives the originally requested functionality (plus a bit extra ;-))

Ben