tris: fix cross-compilation and relocation

_dev/Makefile

@@ -1,5 +1,5 @@
 GO ?= go
-GOENV := $(shell $(GO) env GOOS)_$(shell $(GO) env GOARCH)
+GOENV := $(shell $(GO) env GOHOSTOS)_$(shell $(GO) env GOHOSTARCH)
 GOROOTINFO := $(shell $(GO) version | cut -d' ' -f 3)_$(GOENV)
 
 .PHONY: GOROOT

_dev/go.sh

@@ -4,9 +4,9 @@ set -e
 BASEDIR=$(cd "$(dirname "$0")" && pwd)
 
 make --quiet -C "$BASEDIR" go >&2
-GOENV="$(go env GOOS)_$(go env GOARCH)"
+GOENV="$(go env GOHOSTOS)_$(go env GOHOSTARCH)"
 
-unset GOROOT
+export GOROOT="$BASEDIR/go/$GOENV"
 make --quiet -C "$BASEDIR" GOROOT GO="$BASEDIR/go/$GOENV/bin/go" >&2
 export GOROOT="$BASEDIR/GOROOT/$GOENV"