tree 8317d531f1dfb3ff9e471231b0690673b228a69a
parent 7bcc6a1615c8265eb64d44e6c066ab699577db18
author Russ Cox <rsc@golang.org> 1433876952 -0700
committer Russ Cox <rsc@golang.org> 1434740701 +0000

cmd/go: add preliminary support for vendor directories

When GO15VENDOREXPERIMENT=1 is in the environment,
this CL changes the resolution of import paths according to
the Go 1.5 vendor proposal:

	If there is a source directory d/vendor, then,
	when compiling a source file within the subtree rooted at d,
	import "p" is interpreted as import "d/vendor/p" if that exists.

	When there are multiple possible resolutions,
	the most specific (longest) path wins.

	The short form must always be used: no import path can
	contain “/vendor/” explicitly.

	Import comments are ignored in vendored packages.

The goal of these changes is to allow authors to vendor (copy) external
packages into their source trees without any modifications to the code.
This functionality has been achieved in tools like godep, nut, and gb by
requiring GOPATH manipulation. This alternate directory-based approach
eliminates the need for GOPATH manipulation and in keeping with the
go command's use of directory layout-based configuration.

The flag allows experimentation with these vendoring semantics once
Go 1.5 is released, without forcing them on by default. If the experiment
is deemed a success, the flag will default to true in Go 1.6 and then be
removed in Go 1.7.

For more details, see the original proposal by Keith Rarick at
https://groups.google.com/d/msg/golang-dev/74zjMON9glU/dGhnoi2IMzsJ.

Change-Id: I2c6527e777d14ac6dc43c53e4b3ff24f3279216e
Reviewed-on: https://go-review.googlesource.com/10923
Reviewed-by: Andrew Gerrand <adg@golang.org>