On July 8th, 2026, CircleCI is updating how undeclared parameters are handled. Previously, referencing a parameter that is not declared in the current scope could silently resolve instead of raising an error, allowing invalid configs to compile. After this date, any config that references an undeclared parameter will fail to compile with an undeclared-parameter error. Background This corrects a long-standing issue where invalid configs were silently accepted. As we build the next generation o...