[release-branch.go1.4] code review 189760043: cmd/go: document import path checking

src/cmd/go/doc.go

 // Copyright 2011 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // DO NOT EDIT THIS FILE. GENERATED BY mkdoc.sh.
 // Edit the documentation in other files and rerun mkdoc.sh to generate this one.
 
 /*
 Go is a tool for managing Go source code.
 
@@ skipping 857 matching lines @@
 
 the go tool will verify that https://example.org/?go-get=1 contains the
 same meta tag and then git clone https://code.org/r/p/exproj into
 GOPATH/src/example.org.
 
 New downloaded packages are written to the first directory
 listed in the GOPATH environment variable (see 'go help gopath').
 
 The go command attempts to download the version of the
 package appropriate for the Go release being used.
-Run 'go help install' for more.
+Run 'go help get' for more.
+
+Import path checking
+
+When the custom import path feature described above redirects to a
+known code hosting site, each of the resulting packages has two possible
+import paths, using the custom domain or the known hosting site.
+
+A package statement is said to have an "import comment" if it is immediately
+followed (before the next newline) by a comment of one of these two forms:
+
+        package math // import "path"
+        package math /* import "path" * /
+
+The go command will refuse to install a package with an import comment
+unless it is being referred to by that import path. In this way, import comments
+let package authors make sure the custom import path is used and not a
+direct path to the underlying code hosting site.
+
+See https://golang.org/s/go14customimport for details.
 
 
 Description of package lists
 
 Many commands apply to a set of packages:
 
         go action [packages]
 
 Usually, [packages] is a list of import paths.
 
@@ skipping 213 matching lines @@
 
 The entire test file is presented as the example when it contains a single
 example function, at least one other function, type, variable, or constant
 declaration, and no test or benchmark functions.
 
 See the documentation of the testing package for more information.
 
 
 */
 package main