By default under Hybris 5.6 the generated localextensions.xml is now totally empty (it used to be not) :
<path dir="${HYBRIS_BIN_DIR}" />
<extension name="yempty" />
When you run 'ant all' you can actually see what extensions are loaded :
[echo] core 5.6.0.1 [p*cib]
[echo] testweb 5.6.0.1 [p*w]
[echo] scripting 5.6.0.1 [p*ci]
[echo] paymentstandard 5.6.0.1 [p*ci]
[echo] mediaweb 5.6.0.1 [p*cw]
[echo] maintenanceweb 5.6.0.1 [p*w]
[echo] deliveryzone 5.6.0.1 [p*ci]
[echo] commons 5.6.0.1 [p*ci]
[echo] processing->(scripting,commons) 5.6.0.1 [p*ci]
[echo] impex->processing 5.6.0.1 [p*ci]
[echo] validation->impex 5.6.0.1 [p*ci]
[echo] catalog->(validation,commons) 5.6.0.1 [p*cib]
[echo] europe1->(impex,catalog) 5.6.0.1 [p*ci]
[echo] platformservices->(paymentstandard,impex,deliveryzone,europe1,processing) 5.6.0.1 [p*cb]
[echo] workflow->(catalog,platformservices,processing,commons) 5.6.0.1 [p*ci]
[echo] hac->(impex,catalog,processing,platformservices) 5.6.0.1 [p*w]
[echo] comments->(workflow,impex,catalog,processing) 5.6.0.1 [p*ci]
[echo] advancedsavedquery->(impex,catalog,processing) 5.6.0.1 [p*ci]
[echo] yempty 5.6.0.1 [cibw] path:/Users/*****/Workspace/hybris/hybris/bin/ext-template/yempty
Now the question is what do you want ? Do you want to run a B2C site ? If yes the best way is to run 'ant modulegen' and then add your own extensions, or if you simply want out of the box default sites, add those lines under your localextensions.xml file :
<extension name='apparelstore' />
<extension name='electronicsstore' />
<extension name='yacceleratorcore' />
<extension name='yacceleratorinitialdata' />
<extension name='yacceleratorfacades' />
<extension name='yacceleratorcockpits' />
<extension name='yacceleratorstorefront' />
By doing this you will have out of the box store fronts and HMC / Cockpits.