In $(hotspot_ws)/build/solaris/makefiles/rules.make, it have different build rules for 64 bit and 32 bit. Currently, it explicitly tests whether LP64 equals to 1 or not. This works only when one set LP64=1 as the build option (or ARCH_DATA_MODEL=64). If one set LP64=true or something else, it won't work. The right way of testing whether it is performing 64 bit build or 32 bit is to test whether LP64 exists or not. So we need to change:
ifeq ($(LP64), 1) to
ifdef LP64