diff --git a/clients/android/Makefile b/clients/android/Makefile
index f5e6957ee..5cab0c3ff 100644
--- a/clients/android/Makefile
+++ b/clients/android/Makefile
@@ -7,10 +7,11 @@ install:
 	./check-environment.pl
 	ant debug
 
-dockerdebug:
+env:
 	docker build -t camlistore/android devenv
-	docker run -v $(GOPATH)/src/camlistore.org/clients/android:/src/camlistore -w /src/camlistore camlistore/android ant -Dsdk.dir=/usr/local/android-sdk-linux debug
+
+dockerdebug:
+	docker run -v $(GOPATH)/src/camlistore.org:/src/camlistore.org camlistore/android /src/camlistore.org/clients/android/build-in-docker.pl debug
 
 dockerrelease:
-	docker build -t camlistore/android devenv
-	docker run -i -t -v $(GOPATH)/src/camlistore.org/clients/android:/src/camlistore -v $(HOME)/keys/android-camlistore:/keys -w /src/camlistore camlistore/android ant -Dsdk.dir=/usr/local/android-sdk-linux -Dkey.store=/keys/android-camlistore.keystore -Dkey.alias=camkey release
+	docker run -i -t -v $(GOPATH)/src/camlistore.org:/src/camlistore.org -v $(HOME)/keys/android-camlistore:/keys camlistore/android /src/camlistore.org/clients/android/build-in-docker.pl release
diff --git a/clients/android/assets/camput.arm.oldworks b/clients/android/assets/camput.arm.oldworks
deleted file mode 100755
index 810fbdcef..000000000
Binary files a/clients/android/assets/camput.arm.oldworks and /dev/null differ
diff --git a/clients/android/build-in-docker.pl b/clients/android/build-in-docker.pl
new file mode 100755
index 000000000..50d8c9339
--- /dev/null
+++ b/clients/android/build-in-docker.pl
@@ -0,0 +1,56 @@
+#!/usr/bin/perl
+
+use strict;
+use File::Path qw(make_path);
+
+die "This script is meant to be run within the camlistore/android Docker contain. Run 'make env' to build it.\n"
+    unless $ENV{IN_DOCKER};
+
+my $mode = shift || "debug";
+
+my $ANDROID = "/src/camlistore.org/clients/android";
+my $ASSETS = "$ANDROID/assets";
+my $GENDIR = "$ANDROID/gen/org/camlistore";
+
+umask 0;
+make_path($GENDIR, { mode => 0755 }) unless -d $GENDIR;
+
+$ENV{GOROOT} = "/usr/local/go";
+$ENV{GOBIN} = $GENDIR;
+$ENV{GOPATH} = "/";
+$ENV{GOARCH} = "arm";
+print "Building ARM camlistore.org/cmd/camput\n";
+system("/usr/local/go/bin/go", "install", "camlistore.org/cmd/camput")
+    and die "Failed to build camput";
+
+system("cp", "-p", "$GENDIR/linux_arm/camput", "$ASSETS/camput.arm")
+    and die "cp failure";
+# TODO: build an x86 version too? if/when those Android devices matter.
+
+chdir $ASSETS or  die "can't cd to assets dir";
+
+my $digest = `openssl sha1 camput.arm`;
+chomp $digest;
+print "ARM camput is $digest\n";
+die "No digest" unless $digest;
+write_file("$GENDIR/ChildProcessConfig.java", "package org.camlistore; public final class ChildProcessConfig { // $digest\n}");
+
+print "Running ant $mode\n";
+chdir $ANDROID or die "can't cd to android dir";
+exec "ant",
+    "-Dsdk.dir=/usr/local/android-sdk-linux",
+    "-Dkey.store=/keys/android-camlistore.keystore",
+    "-Dkey.alias=camkey",
+    $mode;
+
+sub write_file {
+    my ($file, $contents) = @_;
+    if (open(my $fh, $file)) {
+        my $cur = do { local $/; <$fh> };
+        return if $cur eq $contents;
+    }
+    open(my $fh, ">$file") or die "Failed to open $file: $!";
+    print $fh $contents;
+    close($fh) or die "Close: $!";
+    print "Wrote $file\n";
+}
diff --git a/clients/android/devenv/Dockerfile b/clients/android/devenv/Dockerfile
index 45bf68f0d..fcd40cec4 100644
--- a/clients/android/devenv/Dockerfile
+++ b/clients/android/devenv/Dockerfile
@@ -3,6 +3,18 @@
 FROM wasabeef/android
 MAINTAINER bradfitz <brad@danga.com>
 
+# Don't need this, since we're just using the archive URL to fetch Go.
+# But it's possible we may want to switch to using hg, in which case:
+# RUN yum -y install mercurial
+
+ENV GOVERS ec5195954667
+RUN cd /usr/local && curl -O http://go.googlecode.com/archive/$GOVERS.zip
+RUN cd /usr/local && unzip -q $GOVERS.zip
+RUN cd /usr/local && mv go-$GOVERS go
+RUN chmod 0755 /usr/local/go/src/make.bash
+RUN echo $GOVERS > /usr/local/go/VERSION
+RUN GOROOT=/usr/local/go GOARCH=arm bash -c "cd /usr/local/go/src && ./make.bash"
+
 # Found these from: android list sdk -u -e
 RUN echo y | android update sdk -u -t android-17
 RUN echo y | android update sdk -u -t build-tools-19.0.1
@@ -15,3 +27,4 @@ ENV PATH $PATH:$ANDROID_HOME/platform-tools
 ENV PATH $PATH:$ANT_HOME/bin
 ENV PATH $PATH:$MAVEN_HOME/bin
 ENV PATH $PATH:$GRADLE_HOME/bin
+ENV IN_DOCKER 1