Put temporary files of test into a directory that's cleaned between workflow runs

.github/workflows/build_and_deploy.yml

@@ -51,6 +51,11 @@ jobs:
         run: |
           npm i -g [email protected]
           corepack enable
+      - name: Check tmp
+        run: |
+          echo ${{ runner.temp }}
+          node -e "const os = require('os'); console.log(os.tmpdir())"
+          node -e "console.log(process.env)"
       - name: Determine deploy target
         # 'force-preview' performs a full preview build but only if acknowledged i.e. workflow_dispatch
         # 'automated-preview' for pushes on branches other than 'canary' for integration testing.

.github/workflows/build_reusable.yml

@@ -276,6 +276,10 @@ jobs:
         # We must use a login shell: fnm installation may modify the `.profile`
         shell: bash -le {0}
         timeout-minutes: ${{ inputs.timeout_minutes }}
+        env:
+          # Used by Node.js in os.tmpdir()
+          # TODO: Make sure our own runners set TEMP to a temp directory that is cleaned up between runs
+          TEMP: ${{ runner.temp }}
 
       # This file messes up the tests because it influences the build root autodetection.
       - name: Clean up stray files