STEPMAKE_DLOPEN
# Do not use bison 1.50 and 1.75.
# 1.29 is required fr %locations, but I'm not sure it's enough --ns
-STEPMAKE_BISON(OPTIONAL, 1.29)
+STEPMAKE_BISON(REQUIRED, 1.29)
STEPMAKE_FLEX(REQUIRED)
STEPMAKE_FLEXLEXER(REQUIRED)
STEPMAKE_FLEXLEXER_LOCATION