(bug) fromJSON leading to a yaml unmarshal error

[tzusman]

This part of my GitHub Action workflow is confirmed to work on Github, but not through act:

strategy:
  matrix: ${{ fromJson(needs.deployments.outputs.deployments) }}

act -l

Error: yaml: unmarshal errors:
  line 153: cannot unmarshal !!str `${{ fro...` into map[string][]interface {}

The deployments output looks something like this:

[
  { "region": "us", "key": "value" },
  { "region": "eu", "key": "value2" }
]

[ssbarnea]

Error: yaml: unmarshal errors:
line 70: cannot unmarshal !!str `${{ mat...` into map[string]string
line 74: cannot unmarshal !!str `${{ mat...` into map[string]string

This is the first thing I got after reading about act and installing it, and that is more than an a month old. The error doesn't even mention the file causing the error! I had to guess.

I run it inside https://github.com/ansible/ansible-lint/blob/master/.github/workflows/tox.yml which does not even have any fromJson in it.

I hope someone looks over it because the act idea is brilliatn, but nobody wants a tool that crashes on first run.

[vecerek]

+1

[github-actions]

Issue is stale and will be closed in 7 days unless there is new activity

[vecerek]

Bump

[ni4]

Got the same issue right after installing the act. Both error lines are like of the previous commenters:
env: ${{ matrix.env }}
Not to mention that everything run smoothly via GHA.

[dsever]

Any workaround?

[github-actions]

Issue is stale and will be closed in 7 days unless there is new activity

[plmercereau]

Well I'm still having this issue and it's a blocking one so I guess it shouldn't be closed

[ShayNehmad-RecoLabs]

This is also blocking for my workflow when working with the FromJson command to develop monorepo workflows:

    runs-on: ubuntu-20.04
    strategy:
      matrix:
        package: ${{ fromJson(needs.provide_packages_json.outputs.matrix) }}

Error:

❯ act -l
Error: yaml: unmarshal errors:
  line 88: cannot unmarshal !!str `${{ fro...` into []interface {}

[catthehacker]

@tzusman @ShayNehmad-RecoLabs could any of you provide full workflow that I can debug on?

[ShayNehmad-RecoLabs]

@catthehacker My example is based on https://tomasvotruba.com/blog/2020/11/16/how-to-make-dynamic-matrix-in-github-actions/

[github-actions]

Issue is stale and will be closed in 14 days unless there is new activity

[lufia]

I think the cause of this error is that YAML parser expects the matrix: a map of array of empty interface. At parsing the workflow, the matrix: will not evaluate yet then the parser get an expression as a string. Therefore the parser cannot parse that workflow.

type Strategy struct {
	FailFast    bool                     `yaml:"fail-fast"`
	MaxParallel int                      `yaml:"max-parallel"`
	Matrix      map[string][]interface{} `yaml:"matrix"`
}
// https://github.com/nektos/act/blob/master/pkg/model/workflow.go#L76

Would change the Matrix field from map[string][]interface{} to interface{} and type cast it every use?

[github-actions]

Issue is stale and will be closed in 14 days unless there is new activity

[pablogs9]

+1