| commit | b99530f7f5dd8e90ff39dedf1cafb4c89d7a5778 | [log] [tgz] |
|---|---|---|
| author | Abhinav Gupta <abg@uber.com> | Mon Nov 04 15:54:56 2019 -0800 |
| committer | GitHub <noreply@github.com> | Mon Nov 04 15:54:56 2019 -0800 |
| tree | 160c9ae27bb78c290c7760e8e9a7e788271a168c | |
| parent | fb77e1d7374710c62cb1dd8cf137415949bf7d19 [diff] |
README: Fix legacy import path instructions (#60)
In migrating to Go modules, we had to decide between the import paths
github.com/uber-go/atomic and go.uber.org/atomic. We chose the latter.
As a result of this, users of the legacy import path would get an error
message similar to the following:
github.com/uber-go/atomic: github.com/uber-go/atomic@v1.5.0: parsing go.mod:
module declares its path as: go.uber.org/atomic
but was required as: github.com/uber-go/atomic
We suggested that users of the legacy import path add the following to
their go.mod.
replace github.com/uber-go/atomic => go.uber.org/atomic v1.5.0
This is inaccurate and will result in the following error message:
go.uber.org/atomic@v1.5.0 used for two different module paths
(github.com/uber-go/atomic and go.uber.org/atomic)
This was not detected before because `go mod tidy` works fine with this
`replace` directive. It fails only when it gets to `go build`.
After digging into this more, per section 4.4 of the resolution section
of [How can I resolve "parsing go.mod: unexpected module path" (..)][1],
the correct method of resolving this is to downgrade the legacy import
path to a version prior to the use of Go modules.
[1]: https://github.com/golang/go/wiki/Modules#how-can-i-resolve-parsing-gomod-unexpected-module-path-and-error-loading-module-requirements-errors-caused-by-a-mismatch-between-import-paths-vs-declared-module-identity
So the correct `replace` directive here would be,
replace github.com/uber-go/atomic => github.com/uber-go/atomic v1.4.0
This fix was verified both, locally and by @atibhav21 who first ran into
this.
Simple wrappers for primitive types to enforce atomic access.
$ go get -u go.uber.org/atomic@v1
As of v1.5.0, the import path go.uber.org/atomic is the only supported way of using this package. If you are using Go modules, this package will fail to compile with the legacy import path path github.com/uber-go/atomic.
We recommend migrating your code to the new import path but if you're unable to do so, or if your dependencies are still using the old import path, you will have to add a replace directive to your go.mod file downgrading the legacy import path to an older version.
replace github.com/uber-go/atomic => github.com/uber-go/atomic v1.4.0
You can do so automatically by running the following command.
$ go mod edit -replace github.com/uber-go/atomic=github.com/uber-go/atomic@v1.4.0
The standard library‘s sync/atomic is powerful, but it’s easy to forget which variables must be accessed atomically. go.uber.org/atomic preserves all the functionality of the standard library, but wraps the primitive types to provide a safer, more convenient API.
var atom atomic.Uint32
atom.Store(42)
atom.Sub(2)
atom.CAS(40, 11)
See the documentation for a complete API specification.
Stable.
Released under the MIT License.