cmd/dist: require Go 1.24.6 as minimum bootstrap toolchain

This is a minimal change to start to require the new minimum bootstrap.
Taking advantage of the newer bootstrap to simplify and improve code is
left to be done in separate CLs.

For golang#69315.

Change-Id: I4bef752b2adb67e969d585d97e680d26afefc6f4
Reviewed-on: https://go-review.googlesource.com/c/go/+/694535
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
Reviewed-by: David Chase <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: dmitshur

doc/next/5-toolchain.md

@@ -4,4 +4,9 @@
 
 ## Linker {#linker}
 
+## Bootstrap {#bootstrap}
 
+<!-- go.dev/issue/69315 -->
+As mentioned in the [Go 1.24 release notes](/doc/go1.24#bootstrap), Go 1.26 now requires
+Go 1.24.6 or later for bootstrap.
+We expect that Go 1.28 will require a minor release of Go 1.26 or later for bootstrap.

src/cmd/dist/README

@@ -4,18 +4,17 @@ As of Go 1.5, dist and other parts of the compiler toolchain are written
 in Go, making bootstrapping a little more involved than in the past.
 The approach is to build the current release of Go with an earlier one.
 
-The process to install Go 1.x, for x ≥ 24, is:
+The process to install Go 1.x, for x ≥ 26, is:
 
-1. Build cmd/dist with Go 1.22.6.
-2. Using dist, build Go 1.x compiler toolchain with Go 1.22.6.
+1. Build cmd/dist with Go 1.24.6.
+2. Using dist, build Go 1.x compiler toolchain with Go 1.24.6.
 3. Using dist, rebuild Go 1.x compiler toolchain with itself.
 4. Using dist, build Go 1.x cmd/go (as go_bootstrap) with Go 1.x compiler toolchain.
 5. Using go_bootstrap, build the remaining Go 1.x standard library and commands.
 
-Because of backward compatibility, although the steps above say Go 1.22.6,
-in practice any release ≥ Go 1.22.6 but < Go 1.x will work as the bootstrap base.
+Because of backward compatibility, although the steps above say Go 1.24.6,
+in practice any release ≥ Go 1.24.6 but < Go 1.x will work as the bootstrap base.
 Releases ≥ Go 1.x are very likely to work as well.
 
-See https://go.dev/s/go15bootstrap for more details about the original bootstrap
-and https://go.dev/issue/54265 for details about later bootstrap version bumps.
-
+See go.dev/s/go15bootstrap for more details about the original bootstrap
+and go.dev/issue/54265 for details about later bootstrap version bumps.

src/cmd/dist/buildtool.go

@@ -121,7 +121,7 @@ var ignoreSuffixes = []string{
 	"~",
 }
 
-const minBootstrap = "go1.22.6"
+const minBootstrap = "go1.24.6"
 
 var tryDirs = []string{
 	"sdk/" + minBootstrap,

src/cmd/dist/notgo122.go renamed to src/cmd/dist/notgo124.go

@@ -2,20 +2,20 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Go 1.24 and later requires Go 1.22.6 as the bootstrap toolchain.
+// Go 1.26 and later requires Go 1.24.6 as the minimum bootstrap toolchain.
 // If cmd/dist is built using an earlier Go version, this file will be
 // included in the build and cause an error like:
 //
 // % GOROOT_BOOTSTRAP=$HOME/sdk/go1.16 ./make.bash
 // Building Go cmd/dist using /Users/rsc/sdk/go1.16. (go1.16 darwin/amd64)
-// found packages main (build.go) and building_Go_requires_Go_1_22_6_or_later (notgo122.go) in /Users/rsc/go/src/cmd/dist
+// found packages main (build.go) and building_Go_requires_Go_1_24_6_or_later (notgo124.go) in /Users/rsc/go/src/cmd/dist
 // %
 //
 // which is the best we can do under the circumstances.
 //
-// See go.dev/issue/44505 for more background on
-// why Go moved on from Go 1.4 for bootstrap.
+// See go.dev/issue/44505 and go.dev/issue/54265 for more
+// background on why Go moved on from Go 1.4 for bootstrap.
 
-//go:build !go1.22
+//go:build !go1.24
 
-package building_Go_requires_Go_1_22_6_or_later
+package building_Go_requires_Go_1_24_6_or_later

src/make.bash

@@ -64,14 +64,14 @@
 # timing information to this file. Useful for profiling where the
 # time goes when these scripts run.
 #
-# GOROOT_BOOTSTRAP: A working Go tree >= Go 1.22.6 for bootstrap.
+# GOROOT_BOOTSTRAP: A working Go tree >= Go 1.24.6 for bootstrap.
 # If $GOROOT_BOOTSTRAP/bin/go is missing, $(go env GOROOT) is
-# tried for all "go" in $PATH. By default, one of $HOME/go1.22.6,
-# $HOME/sdk/go1.22.6, or $HOME/go1.4, whichever exists, in that order.
+# tried for all "go" in $PATH. By default, one of $HOME/go1.24.6,
+# $HOME/sdk/go1.24.6, or $HOME/go1.4, whichever exists, in that order.
 # We still check $HOME/go1.4 to allow for build scripts that still hard-code
 # that name even though they put newer Go toolchains there.
 
-bootgo=1.22.6
+bootgo=1.24.6
 
 set -e
 

src/make.bat

@@ -71,7 +71,7 @@ for /f "tokens=*" %%g in ('where go 2^>nul') do (
 	)
 )
 
-set bootgo=1.22.6
+set bootgo=1.24.6
 if "x%GOROOT_BOOTSTRAP%"=="x" if exist "%HOMEDRIVE%%HOMEPATH%\go%bootgo%" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\go%bootgo%
 if "x%GOROOT_BOOTSTRAP%"=="x" if exist "%HOMEDRIVE%%HOMEPATH%\sdk\go%bootgo%" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\sdk\go%bootgo%
 if "x%GOROOT_BOOTSTRAP%"=="x" set GOROOT_BOOTSTRAP=%HOMEDRIVE%%HOMEPATH%\Go1.4

src/make.rc

@@ -48,7 +48,7 @@ fn bootstrapenv {
 	GOROOT=$GOROOT_BOOTSTRAP GO111MODULE=off GOENV=off GOOS=() GOARCH=() GOEXPERIMENT=() GOFLAGS=() $*
 }
 
-bootgo = 1.22.6
+bootgo = 1.24.6
 GOROOT = `{cd .. && pwd}
 goroot_bootstrap_set = 'true'
 if(~ $"GOROOT_BOOTSTRAP ''){