src/README.vendor - go - Git at Google

 Vendoring in std and cmd
 ========================

 The Go command maintains copies of external packages needed by the
 standard library in the src/vendor and src/cmd/vendor directories.

 There are two modules, std and cmd, defined in src/go.mod and
 src/cmd/go.mod. When a package outside std or cmd is imported
 by a package inside std or cmd, the import path is interpreted
 as if it had a "vendor/" prefix. For example, within "crypto/tls",
 an import of "golang.org/x/crypto/cryptobyte" resolves to
 "vendor/golang.org/x/crypto/cryptobyte". When a package with the
 same path is imported from a package outside std or cmd, it will
 be resolved normally. Consequently, a binary may be built with two
 copies of a package at different versions if the package is
 imported normally and vendored by the standard library.

 Vendored packages are internally renamed with a "vendor/" prefix
 to preserve the invariant that all packages have distinct paths.
 This is necessary to avoid compiler and linker conflicts. Adding
 a "vendor/" prefix also maintains the invariant that standard
 library packages begin with a dotless path element.

 The module requirements of std and cmd do not influence version
 selection in other modules. They are only considered when running
 module commands like 'go get' and 'go mod vendor' from a directory
 in GOROOT/src.

 Maintaining vendor directories
 ==============================

 Before updating vendor directories, ensure that module mode is enabled.
 Make sure that GO111MODULE is not set in the environment, or that it is
 set to 'on' or 'auto', and if you use a go.work file, set GOWORK=off.

 Also, ensure that 'go env GOROOT' shows the root of this Go source
 tree. Otherwise, the results are undefined. It's recommended to build
 Go from source and use that 'go' binary to update its source tree.

 Requirements may be added, updated, and removed with 'go get'.
 The vendor directory may be updated with 'go mod vendor'.
 A typical sequence might be:

     cd src  # or src/cmd
     go get golang.org/x/net@master
     go mod tidy
     go mod vendor

 Use caution when passing '-u' to 'go get'. The '-u' flag updates
 modules providing all transitively imported packages, not only
 the module providing the target package.

 Note that 'go mod vendor' only copies packages that are transitively
 imported by packages in the current module. If a new package is needed,
 it should be imported before running 'go mod vendor'.
	Vendoring in std and cmd
	========================

	The Go command maintains copies of external packages needed by the
	standard library in the src/vendor and src/cmd/vendor directories.

	There are two modules, std and cmd, defined in src/go.mod and
	src/cmd/go.mod. When a package outside std or cmd is imported
	by a package inside std or cmd, the import path is interpreted
	as if it had a "vendor/" prefix. For example, within "crypto/tls",
	an import of "golang.org/x/crypto/cryptobyte" resolves to
	"vendor/golang.org/x/crypto/cryptobyte". When a package with the
	same path is imported from a package outside std or cmd, it will
	be resolved normally. Consequently, a binary may be built with two
	copies of a package at different versions if the package is
	imported normally and vendored by the standard library.

	Vendored packages are internally renamed with a "vendor/" prefix
	to preserve the invariant that all packages have distinct paths.
	This is necessary to avoid compiler and linker conflicts. Adding
	a "vendor/" prefix also maintains the invariant that standard
	library packages begin with a dotless path element.

	The module requirements of std and cmd do not influence version
	selection in other modules. They are only considered when running
	module commands like 'go get' and 'go mod vendor' from a directory
	in GOROOT/src.

	Maintaining vendor directories
	==============================

	Before updating vendor directories, ensure that module mode is enabled.
	Make sure that GO111MODULE is not set in the environment, or that it is
	set to 'on' or 'auto', and if you use a go.work file, set GOWORK=off.

	Also, ensure that 'go env GOROOT' shows the root of this Go source
	tree. Otherwise, the results are undefined. It's recommended to build
	Go from source and use that 'go' binary to update its source tree.

	Requirements may be added, updated, and removed with 'go get'.
	The vendor directory may be updated with 'go mod vendor'.
	A typical sequence might be:

	cd src # or src/cmd
	go get golang.org/x/net@master
	go mod tidy
	go mod vendor

	Use caution when passing '-u' to 'go get'. The '-u' flag updates
	modules providing all transitively imported packages, not only
	the module providing the target package.

	Note that 'go mod vendor' only copies packages that are transitively
	imported by packages in the current module. If a new package is needed,
	it should be imported before running 'go mod vendor'.