gistfile1.txt

*** WARNING: I am going to run 'configure' with no arguments.
*** If you wish to pass any to it, please specify them on the
*** './autogen.sh' command line.

autoreconf: Entering directory `.'
autoreconf: running: autopoint --force
autoreconf: running: aclocal --force 
autoreconf: configure.ac: tracing
autoreconf: running: libtoolize --copy --force
libtoolize: putting auxiliary files in '.'.
libtoolize: copying file './ltmain.sh'
libtoolize: putting macros in AC_CONFIG_MACRO_DIRS, 'm4'.
libtoolize: copying file 'm4/libtool.m4'
libtoolize: copying file 'm4/ltoptions.m4'
libtoolize: copying file 'm4/ltsugar.m4'
libtoolize: copying file 'm4/ltversion.m4'
libtoolize: copying file 'm4/lt~obsolete.m4'
libtoolize: Consider adding '-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
autoreconf: running: /usr/bin/autoconf --force
configure.ac:83: error: possibly undefined macro: PKG_PROG_PKG_CONFIG
      If this token and others are legitimate, please use m4_pattern_allow.
      See the Autoconf documentation.
configure.ac:84: error: possibly undefined macro: PKG_INSTALLDIR
configure.ac:221: error: possibly undefined macro: PKG_CHECK_VAR
autoreconf: /usr/bin/autoconf failed with exit status: 1

I am getting this problem. How is it solved?