Revert "Have CI check for diffs after integration tests"

[aryairani]

Reverts #5798 temporarily; need to change the cache key consistently in a couple of places if we're changing it, related to #5800. I can add more context here, but want to get trunk passing quickly first.

[aryairani]

cc @sellout

[aryairani]

My bad for not anticipating this during review.

[sellout]

Ugh, sorry about this.

This kind of thing comes up a lot because GitHub workflows only partially implement YAML. In particular, they’re missing support for anchors and aliases. But it looks like that might be changing this year.

I’ve done things like generating workflows from Nix, or using some templating script (which are still necessary workarounds if you want to share stuff between workflows or other files, like with our pinned tool versions).

If these cache keys are workflow-local, I think we should just revisit this across workflows once actions/runner#1182 is fixed. Then we can prefix the key with something like &binary-cache-key when caching, and replace the repeated key with *binary-cache-key when restoring. E.g.,

- name: cache ucm binaries
  id: cache-ucm-binaries
  uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4
  with:
    path: ${{env.ucm_local_bin}}
    key: &binary-cache-key ucm-${{ matrix.os }}-${{ hashFiles('**/ci.yaml', '**/stack.yaml', '**/package.yaml', '**/*.hs', '**/unison-cli-integration/integrationtests/IntegrationTests/*')}}
## [...]
- name: restore binaries
  uses: actions/cache/restore@d4323d4df104b026a6aa633fdb11d772146be0bf # v4
  if: steps.cache-transcript-test-results.outputs.cache-hit != 'true'
  with:
    path: ${{env.ucm_local_bin}}
    key: *binary-cache-key
    fail-on-cache-miss: true

And if GitHub ends up supporting merge keys, it can be a bit nicer, as we can anchor the entire with value, then use the merge key (<<) to allow us to still add fail-on-cache-miss to the map.

- name: cache ucm binaries
  id: cache-ucm-binaries
  uses: actions/cache@d4323d4df104b026a6aa633fdb11d772146be0bf # v4
  with: &binary-cache
    path: ${{env.ucm_local_bin}}
    key: ucm-${{ matrix.os }}-${{ hashFiles('**/ci.yaml', '**/stack.yaml', '**/package.yaml', '**/*.hs', '**/unison-cli-integration/integrationtests/IntegrationTests/*')}}
## [...]
- name: restore binaries
  uses: actions/cache/restore@d4323d4df104b026a6aa633fdb11d772146be0bf # v4
  if: steps.cache-transcript-test-results.outputs.cache-hit != 'true'
  with:
    << : *binary-cache
    fail-on-cache-miss: true

But man, all of this stuff just makes me miss Dhall (or at least Nix) for configuration.

[sellout]

This kind of thing comes up a lot because GitHub workflows only partially implement YAML. In particular, they’re missing support for anchors and aliases.

I don’t think it applies in this case any more, but GitHub now supports YAML anchors.