[U-Boot] make config Error

[DH at synoia.com]

installed bison++

Cloned most recent u-boot 2018.06.14

make clean works
make menuconfig fails:
make rpi_3_32b_config fails:

YACC    scripts/kconfig/zconf.tab.c
scripts/kconfig/zconf.y:44 parser name defined to default :"parse"
"scripts/kconfig/zconf.y", line 97: junk after `%%' in definition
section Segmentation fault
scripts/Makefile.lib:228: recipe for target
'scripts/kconfig/zconf.tab.c' failed make[1]: ***
[scripts/kconfig/zconf.tab.c] Error 139


This works on the u-boot version from one month ago.

Suggestions welcome.