[patch] Attached patch resolves the issue

syslog-ng-3.35.1.ebuild.patch (text/plain), 296 bytes, created by Dirk Tilger on 2022-03-15 20:09:44 UTC

--- syslog-ng-3.35.1.ebuild	2022-03-15 20:46:04.236683329 +0100
+++ syslog-ng-3.35.1-r1.ebuild	2022-03-15 20:47:49.393351104 +0100
@@ -43,7 +43,7 @@
 DEPEND="${RDEPEND}
 	test? ( dev-libs/criterion )"
 BDEPEND="
-	sys-devel/bison
+	>=sys-devel/bison-3.7.6
 	sys-devel/flex
 	virtual/pkgconfig"