Bug#1091577: seems to be a bug in autoconf

[Paul Dreik]

Hi,
this failure seems to be due to a bug in autoconf:
https://savannah.gnu.org/support/?110983
...which was patched here:
https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=b71143738516017f0e0d347a4025301c06c40254

thanks github user jirislaby (Jiri Slaby) who tracked this down: 
https://github.com/pauldreik/rdfind/issues/186

Paul (author of rdfind)