1 files changed, 30 insertions, 0 deletions
diff --git a/src/ci/scripts/verify-stable-version-number.sh b/src/ci/scripts/verify-stable-version-number.sh
new file mode 100755
index 000000000..82eb3833c
--- /dev/null
+++ b/src/ci/scripts/verify-stable-version-number.sh
@@ -0,0 +1,30 @@
+#!/bin/bash
+# On the stable channel, check whether we're trying to build artifacts with the
+# same version number of a release that's already been published, and fail the
+# build if that's the case.
+#
+# It's a mistake whenever that happens: the release process won't start if it
+# detects a duplicate version number, and the artifacts would have to be
+# rebuilt anyway.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+if [[ "$(cat src/ci/channel)" != "stable" ]]; then
+    echo "This script only works on the stable channel. Skipping the check."
+    exit 0
+fi
+
+version="$(cat src/version)"
+url="https://static.rust-lang.org/dist/channel-rust-${version}.toml"
+
+if curl --silent --fail "${url}" >/dev/null; then
+    echo "The version number ${version} matches an existing release."
+    echo
+    echo "If you're trying to prepare a point release, remember to change the"
+    echo "version number in the src/version file."
+    exit 1
+else
+    echo "The version number ${version} does not match any released version!"
+    exit 0
+fi