github-pages-deploy-action: Commit fails with "process '/usr/bin/git' failed with exit code 128"

Describe the bug The action fails after Starting to commit changes… with the error message:

##[error]The deploy step encountered an error: The process '/usr/bin/git' failed with exit code 128 ❌

Reproduce Happens with this workflow (worked yesterday): https://github.com/egil/bunit/actions/runs/112644762/workflow

This is the part of the workflow definition that concerns the action:

      - name: Deploy
        uses: JamesIves/github-pages-deploy-action@releases/v3
        with:
          ACCESS_TOKEN: ${{ secrets.GH_DOCS }}
          BRANCH: gh-pages # The branch the action should deploy to.
          FOLDER: docs/_site # The folder the action should deploy.
          CLEAN: true

Logs This is the related part of the log. The full log can be see here: https://github.com/egil/bunit/runs/700410665

2020-05-22T17:44:13.8130700Z ##[group]Run JamesIves/github-pages-deploy-action@releases/v3
2020-05-22T17:44:13.8130829Z with:
2020-05-22T17:44:13.8131267Z   ACCESS_TOKEN: ***
2020-05-22T17:44:13.8131365Z   BRANCH: gh-pages
2020-05-22T17:44:13.8131432Z   FOLDER: docs/_site
2020-05-22T17:44:13.8131518Z   CLEAN: true
2020-05-22T17:44:13.8131608Z env:
2020-05-22T17:44:13.8131692Z   VERSION: 1.0.0-beta-7
2020-05-22T17:44:13.8131779Z   BRANCH: master
2020-05-22T17:44:13.8131846Z   COMMIT: 
2020-05-22T17:44:13.8131931Z   DOCFX_SOURCE_BRANCH_NAME: master
2020-05-22T17:44:13.8132020Z   NBGV_CloudBuildNumber: 1.0.0-beta-7
2020-05-22T17:44:13.8132108Z   NBGV_VersionFileFound: True
2020-05-22T17:44:13.8132201Z   NBGV_VersionOptions: Nerdbank.GitVersioning.VersionOptions
2020-05-22T17:44:13.8132277Z   NBGV_AssemblyVersion: 1.0.0.0
2020-05-22T17:44:13.8132365Z   NBGV_AssemblyFileVersion: 1.0.0.67
2020-05-22T17:44:13.8132457Z   NBGV_AssemblyInformationalVersion: 1.0.0-beta-7+9111ea6f4e
2020-05-22T17:44:13.8132588Z   NBGV_PublicRelease: True
2020-05-22T17:44:13.8132795Z   NBGV_PrereleaseVersion: -beta-7
2020-05-22T17:44:13.8132886Z   NBGV_PrereleaseVersionNoLeadingHyphen: beta-7
2020-05-22T17:44:13.8132975Z   NBGV_SimpleVersion: 1.0.0
2020-05-22T17:44:13.8133061Z   NBGV_BuildNumber: 0
2020-05-22T17:44:13.8133149Z   NBGV_VersionRevision: 67
2020-05-22T17:44:13.8133219Z   NBGV_MajorMinorVersion: 1.0
2020-05-22T17:44:13.8133305Z   NBGV_VersionMajor: 1
2020-05-22T17:44:13.8133391Z   NBGV_VersionMinor: 0
2020-05-22T17:44:13.8133482Z   NBGV_GitCommitId: 9111ea6f4e9bff9a34b7fbf6aed25802ac1c215a
2020-05-22T17:44:13.8133573Z   NBGV_GitCommitIdShort: 9111ea6f4e
2020-05-22T17:44:13.8133662Z   NBGV_GitCommitDate: 5/22/20 4:32:45 PM +00:00
2020-05-22T17:44:13.8133733Z   NBGV_VersionHeight: 67
2020-05-22T17:44:13.8133817Z   NBGV_VersionHeightOffset: 0
2020-05-22T17:44:13.8134075Z   NBGV_Version: 1.0.0.67
2020-05-22T17:44:13.8134159Z   NBGV_BuildMetadataFragment: +9111ea6f4e
2020-05-22T17:44:13.8134245Z   NBGV_NuGetPackageVersion: 1.0.0-beta-7
2020-05-22T17:44:13.8134316Z   NBGV_ChocolateyPackageVersion: 1.0.0-beta-7
2020-05-22T17:44:13.8134401Z   NBGV_NpmPackageVersion: 1.0.0-beta-7
2020-05-22T17:44:13.8134484Z   NBGV_SemVer1: 1.0.0-beta-7
2020-05-22T17:44:13.8134566Z   NBGV_SemVer2: 1.0.0-beta-7
2020-05-22T17:44:13.8134647Z   NBGV_SemVer1NumericIdentifierPadding: 4
2020-05-22T17:44:13.8134734Z   DOTNET_ROOT: /opt/hostedtoolcache/dncs/3.1.202/x64
2020-05-22T17:44:13.8134807Z   GitAssemblyInformationalVersion: 1.0.0-beta-7+9111ea6f4e
2020-05-22T17:44:13.8134894Z   GitBuildVersion: 1.0.0.67
2020-05-22T17:44:13.8134977Z   GitBuildVersionSimple: 1.0.0
2020-05-22T17:44:13.8135062Z ##[endgroup]
2020-05-22T17:44:13.9234989Z Checking configuration and starting deployment… 🚦
2020-05-22T17:44:13.9243286Z Deploying using Access Token… 🔑
2020-05-22T17:44:13.9244987Z Configuring git…
2020-05-22T17:44:14.5360237Z Git configured… 🔧
2020-05-22T17:44:14.5365205Z Starting to commit changes…
2020-05-22T17:44:15.4018938Z ##[error]The deploy step encountered an error: The process '/usr/bin/git' failed with exit code 128 ❌
2020-05-22T17:44:15.4023462Z Deployment Failed ❌