fix(ci): setup mix before running check

.github/workflows/elixir_deps_check.yaml

@@ -16,6 +16,11 @@ jobs:
         uses: actions/checkout@v2.4.0
       - name: ensure rebar
         run: ./scripts/ensure-rebar3.sh 3.16.1-emqx-1
+      - name: setup mix
+        run: |
+          mix local.hex --force
+          mix local.rebar --force
+          mix deps.get
       - name: check elixir deps
         run: ./scripts/check-elixir-deps-discrepancies.exs
 

scripts/check-elixir-deps-discrepancies.exs

@@ -1,8 +1,5 @@
 #!/usr/bin/env elixir
 
-# ensure we have a mix.lock
-{_, 0} = System.cmd("mix", ["deps.get"], into: IO.stream())
-
 # ensure we have a fresh rebar.lock
 
 case File.stat("rebar.lock") do