github.com/rafaeltorres324/go/src@v0.0.0-20210519164414-9fdf653a9838/README.vendor (about) 1 Vendoring in std and cmd 2 ======================== 3 4 The Go command maintains copies of external packages needed by the 5 standard library in the src/vendor and src/cmd/vendor directories. 6 7 In GOPATH mode, imports of vendored packages are resolved to these 8 directories following normal vendor directory logic 9 (see golang.org/s/go15vendor). 10 11 In module mode, std and cmd are modules (defined in src/go.mod and 12 src/cmd/go.mod). When a package outside std or cmd is imported 13 by a package inside std or cmd, the import path is interpreted 14 as if it had a "vendor/" prefix. For example, within "crypto/tls", 15 an import of "golang.org/x/crypto/cryptobyte" resolves to 16 "vendor/golang.org/x/crypto/cryptobyte". When a package with the 17 same path is imported from a package outside std or cmd, it will 18 be resolved normally. Consequently, a binary may be built with two 19 copies of a package at different versions if the package is 20 imported normally and vendored by the standard library. 21 22 Vendored packages are internally renamed with a "vendor/" prefix 23 to preserve the invariant that all packages have distinct paths. 24 This is necessary to avoid compiler and linker conflicts. Adding 25 a "vendor/" prefix also maintains the invariant that standard 26 library packages begin with a dotless path element. 27 28 The module requirements of std and cmd do not influence version 29 selection in other modules. They are only considered when running 30 module commands like 'go get' and 'go mod vendor' from a directory 31 in GOROOT/src. 32 33 Maintaining vendor directories 34 ============================== 35 36 Before updating vendor directories, ensure that module mode is enabled. 37 Make sure GO111MODULE=off is not set ('on' or 'auto' should work). 38 39 Requirements may be added, updated, and removed with 'go get'. 40 The vendor directory may be updated with 'go mod vendor'. 41 A typical sequence might be: 42 43 cd src 44 go get -d golang.org/x/net@latest 45 go mod tidy 46 go mod vendor 47 48 Use caution when passing '-u' to 'go get'. The '-u' flag updates 49 modules providing all transitively imported packages, not only 50 the module providing the target package. 51 52 Note that 'go mod vendor' only copies packages that are transitively 53 imported by packages in the current module. If a new package is needed, 54 it should be imported before running 'go mod vendor'.