Rework docker setup to make it easier to work around bugs on buildbots

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@349234 91177308-0d34-0410-b5e6-96231b3b80d8

utils/docker/debian9/Dockerfile

@@ -109,5 +109,7 @@ RUN apt-get install -y --no-install-recommends \
     python \
     buildbot-slave
 
-ADD scripts /libcxx-scripts/
+ADD scripts/install_clang_packages.sh /tmp/install_clang_packages.sh
-RUN /libcxx-scripts/install_clang_packages.sh
+RUN /tmp/install_clang_packages.sh && rm /tmp/install_clang_packages.sh
+
+RUN git clone https://git.llvm.org/git/libcxx.git /libcxx

utils/docker/scripts/docker_start_buildbots.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -x
+
+# Update the libc++ sources in the image in order to use the most recent version of
+# run_buildbots.sh
+cd /libcxx
+git pull
+source utils/docker/scripts/run_buildbots.sh "$@"

utils/docker/scripts/run_buildbot.sh

@@ -12,6 +12,13 @@ mkdir -p $BOT_DIR
 apt-get update -y
 apt-get upgrade -y
 
+# FIXME(EricWF): Remove this hack. It's only in place to temporarily fix linking libclang_rt from the
+# debian packages.
+# WARNING: If you're not a buildbot, DO NOT RUN!
+apt-get install lld-8
+rm /usr/bin/ld
+ln -s /usr/bin/lld-8 /usr/bin/ld
+
 systemctl set-property buildslave.service TasksMax=100000
 
 buildslave stop $BOT_DIR