#!/usr/bin/env bash
#
# Downgrades every one of our dependencies in Cargo.lock to the
# earliest version listed in our Cargo.toml files.  (And then
# re-upgrades a few second-order dependencies that aren't actually
# supported by our first-order dependencies in their oldest versions.)
#
# The purpose of this script is to make sure that we are actually
# compatible with the versions listed in our Cargo.toml files.
# Without testing this, we could wind up with code that built
# successfully with the versions listed in Cargo.lock, while declaring
# support for versions of our dependencies that won't actually work.

set -euo pipefail

: "${CARGO:=cargo}"

$CARGO +nightly update -Z minimal-versions
$CARGO update \
      -p crc32fast \
      -p zeroize_derive:1.3.2 \
      -p filetime \
      -p tap:1.0.0 \
      -p paste

# The downgraded 'async-fs@2.0.0' lib specifies a dependency of 'futures-lite' 1.2.0,
# but uses `FutureExt::poll()` which wasn't available until 'futures-lite' 1.9.0.
$CARGO update --precise 1.9.0 futures-lite@1.2.0