# Adding a tool upgrades the toolchain to 1.24.0 because older go
# versions fail to parse the tool directive. Issue #74739.
cp go.mod.go1.23.0 go.mod
go get -tool ./mytool
stderr 'go: upgraded go 1.23.0 => 1.24'
cmp go.mod go.mod.go1.24
go mod tidy
cmp go.mod go.mod.go1.24

# No toolchain change if go >= 1.24.0
cp go.mod.go1.24 go.mod
cmp go.mod go.mod.go1.24
go get -tool ./mytool
cmp go.mod go.mod.go1.24
go mod tidy
cmp go.mod go.mod.go1.24

# TODO(#78550): If #78550 is approved, go build should reject
# the go.mod file if go < 1.24 but there is a tool directive.
# For now, we will let it through.
cp go.mod.go1.23.0 go.mod
go list ./mytool
go build -n ./mytool

-- go.mod.go1.23.0 --
module m

go 1.23.0

tool m/mytool
-- go.mod.go1.24 --
module m

go 1.24

tool m/mytool
-- mytool/mytool.go --
package mytool

func main() {}