diff --git a/dashboard/coordinator/main.go b/dashboard/coordinator/main.go
index 2c3c7cca0f..107443dd20 100644
--- a/dashboard/coordinator/main.go
+++ b/dashboard/coordinator/main.go
@@ -54,6 +54,7 @@ var images = map[string]*imageInfo{
 	"gobuilders/linux-x86-base":  {url: "https://storage.googleapis.com/go-builder-data/docker-linux.base.tar.gz"},
 	"gobuilders/linux-x86-gccgo": {url: "https://storage.googleapis.com/go-builder-data/docker-linux.gccgo.tar.gz"},
 	"gobuilders/linux-x86-nacl":  {url: "https://storage.googleapis.com/go-builder-data/docker-linux.nacl.tar.gz"},
+	"gobuilders/linux-x86-sid":   {url: "https://storage.googleapis.com/go-builder-data/docker-linux.sid.tar.gz"},
 }
 
 type buildConfig struct {
@@ -84,6 +85,8 @@ func main() {
 		dashURL:    "https://build.golang.org/gccgo",
 		tool:       "gccgo",
 	})
+	addBuilder(buildConfig{name: "linux-386-sid", image: "gobuilders/linux-x86-sid"})
+	addBuilder(buildConfig{name: "linux-amd64-sid", image: "gobuilders/linux-x86-sid"})
 
 	if (*just != "") != (*rev != "") {
 		log.Fatalf("--just and --rev must be used together")
@@ -378,7 +381,7 @@ func startBuilding(conf buildConfig, rev string) (*buildStatus, error) {
 	container := strings.TrimSpace(string(all))
 	go func() {
 		all, err := exec.Command("docker", "wait", container).CombinedOutput()
-		log.Printf("docker wait %s: %v, %s", container, err, strings.TrimSpace(string(all)))
+		log.Printf("docker wait %s/%s: %v, %s", container, rev, err, strings.TrimSpace(string(all)))
 		donec <- builderRev{conf.name, rev}
 		exec.Command("docker", "rm", container).Run()
 	}()
diff --git a/dashboard/env/linux-x86-sid/Dockerfile b/dashboard/env/linux-x86-sid/Dockerfile
new file mode 100644
index 0000000000..fdbf73d28e
--- /dev/null
+++ b/dashboard/env/linux-x86-sid/Dockerfile
@@ -0,0 +1,14 @@
+# Copyright 2014 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+FROM debian:sid
+MAINTAINER golang-dev <golang-dev@googlegroups.com>
+
+ENV DEBIAN_FRONTEND noninteractive
+
+ADD /scripts/install-apt-deps.sh /scripts/
+RUN /scripts/install-apt-deps.sh
+
+ADD /scripts/build-go-builder.sh /scripts/
+RUN GO_REV=073fc578434b BUILDER_REV=8845ca94a310 /scripts/build-go-builder.sh && test -f /usr/local/bin/builder
diff --git a/dashboard/env/linux-x86-sid/Makefile b/dashboard/env/linux-x86-sid/Makefile
new file mode 100644
index 0000000000..a50b12c856
--- /dev/null
+++ b/dashboard/env/linux-x86-sid/Makefile
@@ -0,0 +1,12 @@
+# Copyright 2014 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+docker: Dockerfile
+	docker build -t gobuilders/linux-x86-sid .
+
+docker-linux.sid.tar.gz: docker
+	docker save gobuilders/linux-x86-sid | gzip | (cd ../../coordinator/buildongce && go run create.go --write_object=go-builder-data/docker-linux.sid.tar.gz)
+
+check: docker
+	docker run gobuilders/linux-x86-sid /usr/local/bin/builder -rev=fa76e8393654 -buildroot=/ -v -report=false linux-amd64-sid
diff --git a/dashboard/env/linux-x86-sid/scripts/build-go-builder.sh b/dashboard/env/linux-x86-sid/scripts/build-go-builder.sh
new file mode 100755
index 0000000000..1448fc567e
--- /dev/null
+++ b/dashboard/env/linux-x86-sid/scripts/build-go-builder.sh
@@ -0,0 +1,20 @@
+set -ex
+
+export GOPATH=/gopath
+export GOROOT=/goroot
+PREFIX=/usr/local
+: ${GO_REV:?"need to be set to the golang repo revision used to build the builder."}
+: ${BUILDER_REV:?"need to be set to the go.tools repo revision for the builder."}
+
+mkdir -p $GOROOT
+curl -s https://storage.googleapis.com/gobuilder/go-snap.tar.gz | tar x --no-same-owner -zv -C $GOROOT
+(cd $GOROOT/src && hg pull -r $GO_REV -u && find && ./make.bash)
+
+GO_TOOLS=$GOPATH/src/code.google.com/p/go.tools
+mkdir -p $GO_TOOLS
+curl -s https://storage.googleapis.com/gobuilder/go.tools-snap.tar.gz | tar x --no-same-owner -zv -C $GO_TOOLS
+
+mkdir -p $PREFIX/bin
+(cd $GO_TOOLS && hg pull -r $BUILDER_REV -u && GOBIN=$PREFIX/bin /goroot/bin/go install code.google.com/p/go.tools/dashboard/builder)
+
+rm -fR $GOROOT/bin $GOROOT/pkg $GOPATH
diff --git a/dashboard/env/linux-x86-sid/scripts/install-apt-deps.sh b/dashboard/env/linux-x86-sid/scripts/install-apt-deps.sh
new file mode 100755
index 0000000000..839f4ad2fa
--- /dev/null
+++ b/dashboard/env/linux-x86-sid/scripts/install-apt-deps.sh
@@ -0,0 +1,17 @@
+set -ex
+
+apt-get update
+# For running curl to get the hg starter tarballs (faster than hg clone).
+apt-get install -y --no-install-recommends curl ca-certificates
+# Optionally used by some net/http tests:
+apt-get install -y --no-install-recommends strace 
+# For building Go's bootstrap 'dist' prog
+apt-get install -y --no-install-recommends gcc libc6-dev
+# For 32-bit builds:
+# TODO(bradfitz): move these into a 386 image that derives from this one.
+apt-get install -y --no-install-recommends libc6-dev-i386 gcc-multilib
+# For interacting with the Go source & subrepos:
+apt-get install -y --no-install-recommends mercurial git-core
+
+apt-get clean
+rm -fr /var/lib/apt/lists