Your package fails to build with the newest autoconf-2.71, which was part of a recent wide Fedora change. More information about Fedora autoconf Change available here: https://fedoraproject.org/wiki/Changes/Autoconf_271#How_To_Test. The easiest way to reproduce the problem is to execute a fedora scratch-build on your package. Thank you for cooperation!
I build it locally, no problems: + exit 0 Finish: rpmbuild libcircle-0.3-8.fc36.src.rpm Finish: build phase for libcircle-0.3-8.fc36.src.rpm INFO: Done(libcircle-0.3-8.fc36.src.rpm) Config(odubaj-autoconf-2.70_fedora-rawhide-x86_64) 4 minutes 31 seconds INFO: Results and/or logs in: /var/lib/mock/odubaj-autoconf-2.70_fedora-rawhide-x86_64/result Finish: run
Failure unrelated to autoconf, but fixed now.