Text file src/README.vendor

Documentation: Index

     1Vendoring in std and cmd
     2========================
     3
     4The Go command maintains copies of external packages needed by the
     5standard library in the src/vendor and src/cmd/vendor directories.
     6
     7There are two modules, std and cmd, defined in src/go.mod and
     8src/cmd/go.mod. When a package outside std or cmd is imported
     9by a package inside std or cmd, the import path is interpreted
    10as if it had a "vendor/" prefix. For example, within "crypto/tls",
    11an import of "golang.org/x/crypto/cryptobyte" resolves to
    12"vendor/golang.org/x/crypto/cryptobyte". When a package with the
    13same path is imported from a package outside std or cmd, it will
    14be resolved normally. Consequently, a binary may be built with two
    15copies of a package at different versions if the package is
    16imported normally and vendored by the standard library.
    17
    18Vendored packages are internally renamed with a "vendor/" prefix
    19to preserve the invariant that all packages have distinct paths.
    20This is necessary to avoid compiler and linker conflicts. Adding
    21a "vendor/" prefix also maintains the invariant that standard
    22library packages begin with a dotless path element.
    23
    24The module requirements of std and cmd do not influence version
    25selection in other modules. They are only considered when running
    26module commands like 'go get' and 'go mod vendor' from a directory
    27in GOROOT/src.
    28
    29Maintaining vendor directories
    30==============================
    31
    32Before updating vendor directories, ensure that module mode is enabled.
    33Make sure that GO111MODULE is not set in the environment, or that it is
    34set to 'on' or 'auto'.
    35
    36Requirements may be added, updated, and removed with 'go get'.
    37The vendor directory may be updated with 'go mod vendor'.
    38A typical sequence might be:
    39
    40    cd src
    41    go get golang.org/x/net@master
    42    go mod tidy
    43    go mod vendor
    44
    45Use caution when passing '-u' to 'go get'. The '-u' flag updates
    46modules providing all transitively imported packages, not only
    47the module providing the target package.
    48
    49Note that 'go mod vendor' only copies packages that are transitively
    50imported by packages in the current module. If a new package is needed,
    51it should be imported before running 'go mod vendor'.

View as plain text