Rerunning old upload actions should not overwrite `julia-latest`

[lgoettgens]

See julia-actions/setup-julia#335.

Yeah, somehow the x86_64-linux-gnu upload job for JuliaLang/julia@c13ea2b ran 6 hours ago. The latest upload job becomes "latest" julia, effectively overwriting possibly newer versions. I can't quite tell why this build started today though.
@giordano

We should probably do a greater than version check
@IanButterworth

[IanButterworth]

I think the way new uploads are assigned as latest nightly might be done on S3? Is that right @staticfloat ?

julia-buildkite/utilities/upload_julia.sh

Lines 133 to 159 in 1a77e50

	# Next, upload primary files to S3
	echo "--- Upload primary products to S3"
	PIDS=()
	for EXT in "${UPLOAD_EXTENSIONS[@]}"; do
	aws s3 cp --acl public-read "${UPLOAD_FILENAME}.${EXT}" "s3://${UPLOAD_TARGETS[0]}.${EXT}" &
	PIDS+=( "$!" )
	done
	wait_pids "${PIDS[@]}"
	echo "--- Copy to secondary upload targets"
	PIDS=()
	# We'll do these in parallel, then wait on the background jobs
	for SECONDARY_TARGET in ${UPLOAD_TARGETS[@]:1}; do
	for EXT in "${UPLOAD_EXTENSIONS[@]}"; do
	aws s3 cp --acl public-read "s3://${UPLOAD_TARGETS[0]}.${EXT}" "s3://${SECONDARY_TARGET}.${EXT}" &
	PIDS+=( "$!" )
	done
	done
	wait_pids "${PIDS[@]}"
	# Report to the user some URLs that they can use to download this from
	echo "+++ Uploaded to targets"
	for UPLOAD_TARGET in ${UPLOAD_TARGETS[@]}; do
	for EXT in "${UPLOAD_EXTENSIONS[@]}"; do
	echo " -> s3://${UPLOAD_TARGET}.${EXT}"
	done
	done

[staticfloat]

Yes, it's the "copy to secondary target" section. You can see all the upload targets defined based on branches and whatnot here:

julia-buildkite/utilities/build_envs.sh

Lines 143 to 153 in b30dd5e

	if [[ "${BUILDKITE_BRANCH}" == master ]] || [[ "${BUILDKITE_BRANCH}" == release-* ]] || [[ "${BUILDKITE_TAG:-}" == v* ]] || [[ "${BUILDKITE_PIPELINE_SLUG}" == "julia-buildkite" ]]; then
	# First, we have the canonical fully-specified upload target
	UPLOAD_TARGETS+=( "${S3_BUCKET}/${S3_BUCKET_PREFIX}/${OS?}/${ARCH?}/${MAJMIN?}/julia-${TAR_VERSION?}-${OS?}-${ARCH?}" )
	# Next, we have the "majmin/latest" upload target
	UPLOAD_TARGETS+=( "${S3_BUCKET}/${S3_BUCKET_PREFIX}/${OS?}/${ARCH?}/${MAJMIN?}/julia-latest-${OS?}-${ARCH?}" )
	# The absolute latest upload target is only for if we're on the `master` branch
	if [[ "${BUILDKITE_BRANCH}" == "master" ]]; then
	UPLOAD_TARGETS+=( "${S3_BUCKET}/${S3_BUCKET_PREFIX}/${OS?}/${ARCH?}/julia-latest-${OS?}-${ARCH?}" )
	fi

IMO, it's a little tricky to determine whether another job uploaded a newer Julia than the one we just built.