fails:Kernel#sprintf is a private method
fails:Kernel#sprintf treats nil arguments as zero-width strings in %s slots
fails:Kernel#sprintf passes some tests for positive %x
fails:Kernel#sprintf passes some tests for negative %x
fails:Kernel#sprintf passes some tests for negative %u
fails:Kernel#sprintf passes some tests for positive %u
fails:Kernel#sprintf passes some tests for positive %d
fails:Kernel#sprintf passes some tests for positive %f
fails:Kernel#sprintf passes some tests for negative %f
fails:Kernel#sprintf passes kstephens's tests
fails:Kernel#sprintf returns a String in the same encoding as the format String if compatible
fails:Kernel#sprintf returns a String in the argument encoding if format encoding is more restrictive
fails:Kernel#sprintf with format string that contains %{} sections substitutes values for named references
fails:Kernel#sprintf with format string that contains %{} sections raises KeyError when no matching key is in second argument
fails:Kernel#sprintf with format string that contains %<> sections formats values for named references
fails:Kernel#sprintf with format string that contains %<> sections raises KeyError when no matching key is in second argument
fails:Kernel#sprintf with negative values with format %x precedes the number with '..'
fails:Kernel#sprintf with negative values with format %b or %B precedes the number with '..'
fails:Kernel.sprintf needs to be reviewed for spec completeness
