Experiments are not shown when baseline commit has an error

[Danila89]

Description

When keeping dvc experiments outside from the main branch, vscode extension fails to show experiments while main branch is active ("Your project contains no data" error is shown).
The issue arises when hydra is used, but up-to-date params.yaml is not present in the current branch.

Reproduce

1. git clone https://github.com/Danila89/dvc_empty.git
2. cd dvc_empty && dvc exp pull origin -A --no-cache
3. At this point we expect to see non-empty "Experiments" tab in VSCode extension (there is one dvc experiment at the repo). But "Your project contains no data" will be shown in VSCode extension
4. To ensure that experiment actually exists: git fetch origin exp1-branch && git checkout --track origin/exp1-branch. This command will populate Experiments tab in VSCode extension with the experiment
5. git checkout master will make Experiments tab empty again

Environment information

Output of dvc doctor:

(base) danila.savenkov@RS-UNIT-0099 dvc_empty % dvc doctor
DVC version: 3.30.1 (pip)
-------------------------
Platform: Python 3.10.9 on macOS-13.3.1-arm64-arm-64bit
Subprojects:
        dvc_data = 2.22.1
        dvc_objects = 1.2.0
        dvc_render = 0.5.3
        dvc_task = 0.3.0
        scmrepo = 1.5.0
Supports:
        http (aiohttp = 3.8.4, aiohttp-retry = 2.8.3),
        https (aiohttp = 3.8.4, aiohttp-retry = 2.8.3),
        s3 (s3fs = 2023.5.0, boto3 = 1.26.76)
Config:
        Global: /Users/danila.savenkov/Library/Application Support/dvc
        System: /Library/Application Support/dvc
Cache types: <https://error.dvc.org/no-dvc-cache>
Caches: local
Remotes: None
Workspace directory: apfs on /dev/disk3s3s1
Repo: dvc, git
Repo.site_cache_dir: /Library/Caches/dvc/repo/446173993f470ed3f55e59a2478cfe4e

Output of dvc exp show -n 3 --json:

(base) danila.savenkov@RS-UNIT-0099 dvc_empty % dvc exp show -n 3 --json
[
  {
    "rev": "workspace",
    "name": null,
    "data": null,
    "error": {
      "msg": "failed to parse 'stages.main.cmd' in 'dvc.yaml': Could not find 'parameters.parameter_name'",
      "type": "ResolveError"
    },
    "experiments": null
  },
  {
    "rev": "616500724541bcd2f7f89584187b00f838ecf9a9",
    "name": "master",
    "data": null,
    "error": {
      "msg": "failed to parse 'stages.main.cmd' in 'dvc.yaml': Could not find 'parameters.parameter_name'",
      "type": "ResolveError"
    },
    "experiments": [
      {
        "revs": [
          {
            "rev": "ee23879da223ff9d5bd906bdd8969cc0ea90344f",
            "name": "exp1",
            "data": {
              "rev": "ee23879da223ff9d5bd906bdd8969cc0ea90344f",
              "timestamp": "2023-11-28T16:07:17",
              "params": {
                "params.yaml": {
                  "data": {
                    "parameters": {
                      "parameter_name": "parameter_value"
                    }
                  }
                },
                "dvclive/params.yaml": {
                  "data": {
                    "result": 0.6936822634315442
                  }
                }
              },
              "metrics": {},
              "deps": {},
              "outs": {},
              "meta": {}
            },
            "error": null,
            "experiments": null
          }
        ],
        "executor": null,
        "name": "exp1"
      }
    ]
  },
  {
    "rev": "7d527bc6ae94befdc9352e59d80b133cdb0a1e7a",
    "name": null,
    "data": {
      "rev": "7d527bc6ae94befdc9352e59d80b133cdb0a1e7a",
      "timestamp": "2023-11-28T15:57:50",
      "params": {},
      "metrics": {},
      "deps": {},
      "outs": {},
      "meta": {}
    },
    "error": null,
    "experiments": null
  },
  {
    "rev": "19825884a7acacc3177716c8fd7b2502ed129c59",
    "name": null,
    "data": {
      "rev": "19825884a7acacc3177716c8fd7b2502ed129c59",
      "timestamp": "2023-11-28T13:09:17",
      "params": {},
      "metrics": {},
      "deps": {},
      "outs": {},
      "meta": {}
    },
    "error": null,
    "experiments": null
  }
]

[mattseddon]

@Danila89

In the data for the current commit on master you have an error instead of data:

    "error": {
      "msg": "failed to parse 'stages.main.cmd' in 'dvc.yaml': Could not find 'parameters.parameter_name'",
      "type": "ResolveError"
    }

The extension could be showing "your project has no data" instead of the error which would be a bug.

Thanks for providing the repo should make things easier to solve. I'll be taking a deeper look shortly.

[Danila89]

Just to mention: the nature of this error is kind of obvious (master branch does not know about parameters.parameter_name because of the lack of params.yaml. But the error does not prevent dvc exp show correct work and I wish that it won't prevent VSCode extension correct work as well.
Seems that this issue could be related (also about errors with hydra and params.yaml)