"unknown input name provided" when input does exist

In GitLab 18.1.0-pre 4a5e7cf522f, I ran into this error:

Unable to create pipeline
`component.yml`: unknown input name provided: `313`

In the documentation we can find about this topic:

• CI/CD YAML syntax reference > spec:inputs
• CI/CD inputs

I do not see any mention anything that sound meaningful for this error.

The following MRE is a repo located here.

# .gitlab-ci.yml
include:
  - project: $CI_PROJECT_PATH
    ref: $CI_COMMIT_REF_NAME
    file: component.yml

# component.yml
spec:
  inputs:
    313:
      default: "Default"

---

job:
  script:
    - echo $[[ inputs.313 ]]

The pipeline result can be found here.

313 is deserialised as a number but in gitlab's microlanguage (i.e. echo $[[ inputs.313 ]]) the 313 is interpreted as a string.

To fix this, you need to quote the input name: .

# component.yml
spec:
  inputs:
    "313":
      default: "Default"

---

job:
  script:
    - echo $[[ inputs.313 ]]

# .gitlab-ci.yml
include:
  - project: $CI_PROJECT_PATH
    ref: $CI_COMMIT_REF_NAME
    file: component.yml
    inputs:
      "313": "Custom"

Notes that the include:inputs:"313:" section names also require quotes.

Answer based on the findings of @Dunes, see his comment.