I'm trying to build pike/7.5 from CVS. I'm using autoconf-2.57. The generated configure script contains

# So? What about this header? case $ac_header_compiler:$ac_header_preproc in yes:no fi

which leads to syntax error when running it. Perhaps it's the recursive use of AC_CHECK_HEADERS

dnl Checking for version 2+ API AC_CHECK_HEADERS(linux/dvb/version.h, [ AC_CHECK_HEADERS(linux/dvb/sec.h, [PIKE_FEATURE(DVB,[yes (version 2 api)])], [PIKE_FEATURE(DVB,[no (missing linux/dvb/sec.h - version 3 api?)]) ]) ])

that for some reason won't work. For now, I just replaced the tests with a PIKE_FEATURE(DVB,[no (disabled)]) to be able to compile.