A value range for a code development option, which results in an error when applied to a given code, can be automatically searched to intelligently identify a threshold for the error within the value range. Instead of completely abandoning the optimizations offered by a code development option with a value range, the code development option as applied to a given code can be limited to a subrange of the value range, thus imbuing the given code with at least the optimizations offered by the code development option with the subrange. A failure analysis tool searches, for example according to binary search, a value range. Subranges are applied to the given code and results examined to influence successive selections of subranges. Eventually, a threshold, if any, is discovered that separates a subrange that does not result in error from a subrange that results in error.