I am uploading a NMU to fix this. The debdiff is attached.
diff -Nru farpd-0.2/debian/changelog farpd-0.2/debian/changelog
--- farpd-0.2/debian/changelog 2023-08-18 00:18:37.000000000 +0200
+++ farpd-0.2/debian/changelog 2023-09-05 22:05:19.000000000 +0200
@@ -1,3 +1,10 @@
+farpd (0.2-11.3) unstable; urgency=medium
+
+ * Non-maintainer upload
+ * Prevent searching for libevent.a (Closes: #1051291)
+
+ -- Bastian Germann <b...@debian.org> Tue, 05 Sep 2023 22:05:19 +0200
+
farpd (0.2-11.2) unstable; urgency=medium
* Non-maintainer upload
diff -Nru farpd-0.2/debian/patches/debian.patch
farpd-0.2/debian/patches/debian.patch
--- farpd-0.2/debian/patches/debian.patch 2023-08-18 00:18:37.000000000
+0200
+++ farpd-0.2/debian/patches/debian.patch 2023-09-05 21:53:01.000000000
+0200
@@ -224,7 +224,7 @@
;;
esac ],
-[ if test -f ${prefix}/include/event.h -a -f ${prefix}/lib/libevent.a;
-+[ if test -f ${prefix}/include/event.h -a -f ${prefix}/lib/${host}/libevent.a;
++[ if test -f ${prefix}/include/event.h;
then
EVENTINC="-I${prefix}/include"
EVENTLIB="-L${prefix}/lib -levent"