Of course it's now available from Leopard...

And 10.6 was Snow Leopard. And 10.7 was Lion. Then Mountain Lion...

Source/Managers/SuitManager.swift

@@ -130,7 +130,7 @@ public class SuitManager: McuManager {
         let roles = response.manifests.compactMap(\.role)
         self.roleIndex = 0
         self.roles = roles
-        if #available(iOS 13.0, macOS 10.5, *) {
+        if #available(iOS 13.0, macOS 10.15, *) {
             let rolesList = ListFormatter.localizedString(byJoining: roles.map(\.description))
             self.logDelegate?.log("Received Response with Roles: \(rolesList)", ofCategory: .suit, atLevel: .debug)
         }