debian/changelog

+cdk (1:2.3-2) unstable; urgency=medium
+
+  * Manually removing version constraint of libsignatures-java from
+    libcdk-java.substvars.
+
+ -- Andrius Merkys <merkys@debian.org>  Tue, 31 Dec 2019 02:33:01 -0500
+
 cdk (1:2.3-1) unstable; urgency=medium
 
   [ Andreas Tille ]

debian/rules

 #!/usr/bin/make -f
 
 %:
-	dh $@
\ No newline at end of file
+	dh $@
+
+# Version of libsignatures-java (0.0~...) is different from the one
+# given in its pom.xml, thus it has to be removed manually.
+override_dh_auto_install:
+	dh_auto_install
+	sed -i 's/libsignatures-java (>= 1.2-SNAPSHOT)/libsignatures-java/' debian/libcdk-java.substvars