Set the GDML_SCHEMA_DIR environment variable to point to the local directory.
GDML_SCHEMA_DIR=/mySchemaDir
SLIC also searches automatically in the current directory for schemas.
The entity resolver in GDML should find the schemas if the structure has been flattened (all .xsd files in mySchemaDir, no subdirectories).
SLIC should also be able to find the schemas when the path component of the URL is preserved, i.e. ./schemas/lcdd/1.0/lcdd.xsd.
Specific for ilcinstall
The GDML schemas needed are already saved in the ilcinstall installation directory, so all that's needed is to point to them:
GDML_SCHEMA_DIR=v00-00/geant4/9.6.p01/source/persistency/gdml/schema/
Downloading the LCDD schemas (not necessary for default ilcinstall)
To copy the schemas into a local directory, do the following.
cvs -d :pserver:anonymous@cvs.freehep.org:/cvs/lcd co lcdd cp lcdd/schemas/*/*/*.xsd /mySchemaDir
If you want to keep the schema directory structure, use this command from your lcdd directory.
cp -R schemas /mySchemaDir