xs/vendor/github.com/pkg/errors/README.md
Russ Magee f5be3578a8 1/3 Updated Makefile to allow VENDOR flag (adds -vendor to version string)
2/3 Added vendor/ dir to lock down dependent pkg versions.
The author of git.schwanenlied.me/yawning/{chacha20,newhope,kyber}.git has copied
their repos to gitlab.com/yawning/ but some imports of chacha20 from newhope still
inconsistently refer to git.schwanenlied.me/, breaking build.
Licenses for chacha20 also changed from CC0 to AGPL, which may or may not be an
issue. Until the two aforementioned issues are resolved, locking to last-good
versions is probably the best way forward for now.

To build with vendored deps, use make VENDOR=1 clean all

3/3 Moved body of CI push script into bacillus/
2020-01-29 17:23:44 -08:00

2.3 KiB

errors Travis-CI AppVeyor GoDoc Report card Sourcegraph

Package errors provides simple error handling primitives.

go get github.com/pkg/errors

The traditional error handling idiom in Go is roughly akin to

if err != nil {
        return err
}

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.

Adding context to an error

The errors.Wrap function returns a new error that adds context to the original error. For example

_, err := ioutil.ReadAll(r)
if err != nil {
        return errors.Wrap(err, "read failed")
}

Retrieving the cause of an error

Using errors.Wrap 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.Wrap to retrieve the original error for inspection. Any error value which implements this interface can be inspected by errors.Cause.

type causer interface {
        Cause() error
}

errors.Cause will recursively retrieve the topmost error which does not implement causer, which is assumed to be the original cause. For example:

switch err := errors.Cause(err).(type) {
case *MyError:
        // handle specifically
default:
        // unknown error
}

Read the package documentation for more information.

Contributing

We welcome pull requests, bug fixes and issue reports. With that said, the bar for adding new symbols to this package is intentionally set high.

Before proposing a change, please discuss your change by raising an issue.

License

BSD-2-Clause