make.bat: building on Windows fails if existing toolchain path contains space

[kevpar]

What version of Go are you using (go version)?

> go version
go version go1.19.3 windows/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

> go env
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\kevpar\AppData\Local\go-build
set GOENV=C:\Users\kevpar\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\kevpar\go\pkg\mod
set GOOS=windows
set GOPATH=C:\Users\kevpar\go
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=C:\Program Files\Go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=C:\Program Files\Go\pkg\tool\windows_amd64
set GOVCS=
set GOVERSION=go1.19.3
set GCCGO=gccgo
set GOAMD64=v1
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\Users\kevpar\src\go\src\go.mod
set GOWORK=
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=C:\Users\kevpar\AppData\Local\Temp\go-build2642396807=/tmp/go-build -gno-record-gcc-switches

What did you do?

1. Installed Go on Windows via the standard installer, which installed it to "C:\Program Files\Go"
2. Open the Go repo
3. cd src
4. .\make.bat

What did you expect to see?

The Go repo should successfully build.

What did you see instead?

>.\make.bat
ERROR: Cannot find C:\Users\kevpar\Go1.4\bin\go.exe
Set GOROOT_BOOTSTRAP to a working Go tree >= Go 1.17.13.

Details

This error occurs under the following conditions:

• The path containing the existing go toolchain (output of where go) contains a space
• GOROOT_BOOTSTRAP, which explicitly specifies the GOROOT to use when building, is unset

The error is caused because the output of where go is used without wrapping the path in spaces here.

[gopherbot]

Change https://go.dev/cl/462275 mentions this issue: make.bat: support existing toolchain paths with spaces