Use PYTHON_FOR_BUILD instead of calling python directly

Change-Id: I85ff669c3cfd6d9b3284972cfa1d8a805ea3b6d4
Reviewed-on: https://gerrit.libreoffice.org/49637Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

postprocess/CustomTarget_images.mk

@@ -33,7 +33,7 @@ $(packimages_DIR)/%.zip : \
 	$(call gb_Output_announce,$(subst $(WORKDIR)/,,$@),$(true),PRL,2)
 	$(call gb_Helper_abbreviate_dirs, \
 		ILSTFILE=$(call var2file,$(shell $(gb_MKTEMP)),100,$(filter %.ilst,$^)) && \
-		$(PYTHON) $(SRCDIR)/solenv/bin/pack_images.py \
+		$(PYTHON_FOR_BUILD) $(SRCDIR)/solenv/bin/pack_images.py \
 			$(if $(DEFAULT_THEME),\
 				-g $(packimages_DIR) -m $(packimages_DIR) -c $(packimages_DIR),\
 				-g $(SRCDIR)/icon-themes/$(subst images_,,$*) -m $(SRCDIR)/icon-themes/$(subst images_,,$*) -c $(SRCDIR)/icon-themes/$(subst images_,,$*) \

testtools/source/bridgetest/pyuno/makefile.mk

@@ -46,7 +46,7 @@ REGEXC=$(DLLDEST)$/regcomp$(EXECPOST)
 .IF "$(SYSTEM_PYTHON)"!="YES"
 PYTHON=$(AUGMENT_LIBRARY_PATH) $(WRAPCMD) $(SOLARBINDIR)/python
 .ELSE                   # "$(SYSTEM_PYTHON)"!="YES"
-PYTHON=$(AUGMENT_LIBRARY_PATH) $(WRAPCMD) python
+PYTHON=$(AUGMENT_LIBRARY_PATH) $(WRAPCMD) $(PYTHON_FOR_BUILD)
 .ENDIF                  # "$(SYSTEM_PYTHON)"!="YES"
 .IF "$(OS)"=="WNT"
 PYTHONPATH:=$(SOLARLIBDIR)$/pyuno;$(PWD);$(SOLARLIBDIR);$(SOLARLIBDIR)$/python;$(SOLARLIBDIR)$/python$/lib-dynload