cmd/go: document GOCACHEPROG in go help environment

This adds GOCACHEPROG to the list of environment variables in "go help
environment" and points to the cacheprog package documentation for
details of the protocol.

Fixes #71032
Updates #59719

Change-Id: Ib8f5804926a8fa59237661076d129c2852665ac3
Reviewed-on: https://go-review.googlesource.com/c/go/+/638997
Auto-Submit: Austin Clements <austin@google.com>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 910699caced7e85598014b15cd3dd5d140d63672..88f2e21f822d1a45195a402f7bbe2e10ac8f7eee 100644 (file)
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -2333,6 +2333,10 @@
 //     GOCACHE
 //             The directory where the go command will store cached
 //             information for reuse in future builds.
+//     GOCACHEPROG
+//             A command (with optional space-separated flags) that implements an
+//             external go command build cache.
+//             See 'go doc cmd/go/internal/cacheprog'.
 //     GODEBUG
 //             Enable various debugging facilities. See https://go.dev/doc/godebug
 //             for details.

diff --git a/src/cmd/go/internal/help/helpdoc.go b/src/cmd/go/internal/help/helpdoc.go
index 7e19ba93d2a83d7257b30ea9b3f0f9bc4e840084..311584d4f0f1f3aa1ce695e4010f166c3a69eff3 100644 (file)
--- a/src/cmd/go/internal/help/helpdoc.go
+++ b/src/cmd/go/internal/help/helpdoc.go
@@ -506,6 +506,10 @@ General-purpose environment variables:
        GOCACHE
                The directory where the go command will store cached
                information for reuse in future builds.
+       GOCACHEPROG
+               A command (with optional space-separated flags) that implements an
+               external go command build cache.
+               See 'go doc cmd/go/internal/cacheprog'.
        GODEBUG
                Enable various debugging facilities. See https://go.dev/doc/godebug
                for details.