Privoxy uses configure.in file, but this file name is deprecated since autoconf-2.50 released in 2001 and it is officially recommended to rename it to configure.ac:
https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/Writing-Autoconf-Input.html
Thanks for the suggestion but updating the autoconf goo
is already on the TODO list:
http://ijbswa.cvs.sourceforge.net/viewvc/ijbswa/current/TODO?view=markup#l173
I don't consider the file name a bug, though, and think updating
the file name can wait until the content is updated as well,
at which point we risk breaking stuff for less commonly used
platforms anyway.
Updated TODO list link:
https://www.privoxy.org/gitweb/?p=privoxy.git;a=blob;f=TODO;hb=HEAD#l155