Hi, I opened a similar issue, please take a look https://bugs.gentoo.org/668404 The solution for this project is just executing the command 'autoconf --force configure.ac > configure' from the root of the project
Fixed since https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=dd253feed23adc325b7e6bcf4415c2dd5f4f42f6.