Package errors provides simple error handling primitives. The traditional error handling idiom in Go is roughly akin to which applied recursively up the call stack results in error reports without context or debugging information. The errors package allows programmers to add context to the failure path in their code in a way that does not destroy the original value of the error. The errors.Annotate function returns a new error that adds context to the original error by recording a stack trace at the point Annotate is called, and the supplied message. For example If additional control is required the errors.AddStack and errors.WithMessage functions destructure errors.Annotate into its component operations of annotating an error with a stack trace and an a message, respectively. Using errors.Annotate constructs a stack of errors, adding context to the preceding error. Depending on the nature of the error it may be necessary to reverse the operation of errors.Annotate to retrieve the original error for inspection. Any error value which implements this interface can be inspected by errors.Cause. errors.Cause will recursively retrieve the topmost error which does not implement causer, which is assumed to be the original cause. For example: causer interface is not exported by this package, but is considered a part of stable public API. errors.Unwrap is also available: this will retrieve the next error in the chain. All error values returned from this package implement fmt.Formatter and can be formatted by the fmt package. The following verbs are supported New, Errorf, Annotate, and Annotatef record a stack trace at the point they are invoked. This information can be retrieved with the StackTracer interface that returns a StackTrace. Where errors.StackTrace is defined as The Frame type represents a call site in the stack trace. Frame supports the fmt.Formatter interface that can be used for printing information about the stack trace of this error. For example: See the documentation for Frame.Format for more details. errors.Find can be used to search for an error in the error chain.