earthly: Cache export hangs on target with just `BUILD` commands, and no `FROM` in the base target

I am using earthly with GitHub Actions and the following earthly command:

earthly --ci --remote-cache=ghcr.io/notin-dev/cache:cache --push +build-all

The entire build is taking about 8 minutes to complete, but the cache step is taking over 20 minutes to complete and I get the following output

cache | --> exporting cache
[653](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:653)
               cache | [          ]   0% preparing build cache for export
[654](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:654)
               cache | [██████████] 100% preparing build cache for export
[655](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:655)
             ongoing | cache (1 minute ago)
[656](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:656)
             ongoing | cache (2 minutes ago)
[657](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:657)
             ongoing | cache (3 minutes ago)
[658](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:658)
             ongoing | cache (4 minutes ago)
[659](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:659)
             ongoing | cache (5 minutes ago)
[660](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:660)
             ongoing | cache (6 minutes ago)
[661](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:661)
             ongoing | cache (7 minutes ago)
[662](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:662)
             ongoing | cache (8 minutes ago)
[663](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:663)
             ongoing | cache (9 minutes ago)
[664](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:664)
             ongoing | cache (10 minutes ago)
[665](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:665)
             ongoing | cache (11 minutes ago)
[666](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:666)
             ongoing | cache (12 minutes ago)
[667](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:667)
             ongoing | cache (13 minutes ago)
[668](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:668)
             ongoing | cache (14 minutes ago)
[669](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:669)
             ongoing | cache (15 minutes ago)
[670](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:670)
             ongoing | cache (16 minutes ago)
[671](https://github.com/notin-dev/lomp/runs/6957678719?check_suite_focus=true#step:5:671)
             ongoing | cache (17 minutes ago)

I initially though that the issue was with heavy usage of SAVE IMAGE --cache-hint and so I removed every occurrence of that in the repository but even then the cache step is taking forever to complete.

I’m not sure if I’m doing something wrong here.

This is my GitHub Actions file:

name: Build Project
on:
  pull_request:
    branches: [main]
  push:
    branches:
      - main
concurrency:
  group: ${{ github.head_ref || github.ref }}
  cancel-in-progress: true
jobs:
  build_project:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2
      - name: Logging into Container Registry
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Installing earthly
        run: sudo /bin/sh -c 'wget https://github.com/earthly/earthly/releases/download/v0.6.14/earthly-linux-amd64 -O /usr/local/bin/earthly && chmod +x /usr/local/bin/earthly'
      - name: Building project
        run: earthly --ci --remote-cache=ghcr.io/notin-dev/cache:cache --push +build-all