Check your version of autoconf and compare to AC_PREREQ in aclocal.m4. Try re-installing autotools if something doesn't work.
On my focal 20.04 LTS, following https://www.libraw.org/docs/Install-LibRaw.html
$ apt-cache policy pkg-config
pkg-config:
Installed: 0.29.1-0ubuntu4...
$ apt-cache policy automake
automake:
Installed: 1:1.16.1-4ubuntu6...
$apt-cache policy libtool
libtool:
Installed: 2.4.6-14...
$ autoconf -V
autoconf (GNU Autoconf) 2.69....
$ cd
$ git clone https://github.com/LibRaw/LibRaw.git
$ cd LibRaw
$ autoreconf --install
$ ./configure
$ make
$ bin/raw-identify
Usage: /home/ib/LibRaw/bin/.libs/raw-identify [options] inputfiles
Options:
-v verbose output
-w print white balance
-u print unpack function
-f print frame size (only w/ -u)
-s print output image size
-h force half-size mode (only for -s)
-M disable use of raw-embedded color data
+M force use of raw-embedded color data
-L filename read input files list from filename
-o filename output to filename
Check your version of autoconf and compare to AC_PREREQ in aclocal.m4. Try re-installing autotools if something doesn't work.
On my focal 20.04 LTS, following https://www.libraw.org/docs/Install-LibRaw.html