[libc++] Clean up scripts to setup CI on macOS

libcxx/docs/AddingNewCIJobs.rst

@@ -17,7 +17,7 @@ If you need to run the job on your own machines, please follow the
 `Buildkite guide <https://buildkite.com/docs/agent/v3>`_ to setup your
 own agents. Make sure you tag your agents in a way that you'll be able
 to recognize them when defining your job below. Finally, in order for the
-agent to register itself to Buildkite, it will need a ``BUILDKITE_AGENT_TOKEN``.
+agent to register itself to Buildkite, it will need a BuildKite Agent token.
 Please contact a maintainer to get your token.
 
 Then, simply add a job to the Buildkite pipeline by editing ``libcxx/utils/ci/buildkite-pipeline.yml``.

libcxx/utils/ci/macos-ci-setup

@@ -4,7 +4,10 @@
 # An additional requirement that is *not* handled by this script is the
 # installation of Xcode, which requires manual intervention.
 
-source secrets.env
+if [[ -z "${BUILDKITE_AGENT_TOKEN}" ]]; then
+  echo "The BUILDKITE_AGENT_TOKEN environment variable must be set to a BuildKite Agent token when calling this script."
+  exit 1
+fi
 
 # Install Homebrew
 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

libcxx/utils/ci/secrets.env

@@ -1,8 +0,0 @@
-#
-# This file template shows which environment variables are required to run
-# libc++ CI nodes. The actual values of these tokens must obviously never be
-# checked in.
-#
-
-# Required to register a new agent with Buildkite
-BUILDKITE_AGENT_TOKEN=<secret>