Try removing the CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND options from the Raspberry Pi defconfig. This causes an infinite loop which eats all memory on the build machine. Normally build errors or hangs are not treated as very high severity, but given that this can take down the build machine, it's important enough to solve before zeus is released.
The problem is due to the Kconfig script asking over and over for those parameters, filling up the entire log, and the memory. This is related to the cml1_do_configure function in poky, which keep this infinite loop going by submitting constant newlines.