TESTGO_GOROOT=<GOROOT used to build cmd/go, for use in tests that may change GOROOT>
	HOME=/no-home
	PATH=<actual PATH>
	TMPDIR=$WORK/tmp
	GODEBUG=<actual GODEBUG>
	devnull=<value of os.DevNull>
	goversion=<current Go version; for example, 1.12>

On Plan 9, the variables $path and $home are set instead of $PATH and $HOME.
On Windows, the variables $USERPROFILE and $TMP are set instead of
$HOME and $TMPDIR.

	./all.bash

To run tests on the Android device, add the bin directory to PATH so the
go tool can find the go_android_$GOARCH_exec wrapper generated by
make.bash. For example, to run the go1 benchmarks

	export PATH=$GOROOT/bin:$PATH
	cd $GOROOT/test/bench/go1/

requiring specific network servers and also to make them 
significantly faster.

A small go get'able test module can be added here by running

	cd cmd/go/testdata
	go run addmod.go path@vers

where path and vers are the module path and version to add here.

For interactive experimentation using this set of modules, run:

	cd cmd/go
	go test -proxy=localhost:1234 &
	export GOPROXY=http://localhost:1234/mod