The problem with autoconf 2.63 seems to be:
| config.status: creating make_variables | awk: string too long near line 3 | awk: newline in string near line 3 | awk: syntax error near line 4 | awk: illegal statement near line 4 | awk: string too long near line 4 | awk: newline in string near line 4 | config.status: creating Makefile | awk: string too long near line 3 | awk: newline in string near line 3 | awk: syntax error near line 4 | awk: illegal statement near line 4 | awk: string too long near line 4 | awk: newline in string near line 4 | config.status: creating clf_machine.h
Probably a case of using GNU extensions to awk...