My workflow includes cloning Fast-DDS repo v1.8.x branch and building it wusing CMake and installing on build machine.
Running the action results in git error:

Set up job4s
Download action repository 'actions/upload-release-asset@v1'
Current runner version: '2.273.1'
Operating System
  Ubuntu
  18.04.5
  LTS
Virtual Environment
  Environment: ubuntu-18.04
  Version: 20200908.1
  Included Software: https://github.com/actions/virtual-environments/blob/ubuntu18/20200908.1/images/linux/Ubuntu1804-README.md
Prepare workflow directory
Prepare all required actions
Download action repository 'actions/checkout@v2'
Download action repository 'actions/create-release@latest'
Download action repository 'actions/upload-release-asset@v1'
Run actions/checkout@v2

with:

repository: eProsima/Fast-DDS.git

ref: 1.18.x

path: Fast-DDS

token: ***

ssh-strict: true

persist-credentials: true

clean: true

fetch-depth: 1

lfs: false

submodules: false

env:

BUILD_TYPE: Release

Syncing repository: eProsima/Fast-DDS.git

Getting Git version info

Working directory is '/home/runner/work/ActuialRepoName/ActuialRepoName/Fast-DDS'

/usr/bin/git version

git version 2.28.0

Initializing the repository

/usr/bin/git init /home/runner/work/ActuialRepoName/ActuialRepoName/Fast-DDS

Initialized empty Git repository in /home/runner/work/ActuialRepoName/ActuialRepoName/Fast-DDS/.git/

/usr/bin/git remote add origin https://github.com/eProsima/Fast-DDS.git

Disabling automatic garbage collection

/usr/bin/git config --local gc.auto 0

Setting up auth

/usr/bin/git config --local --name-only --get-regexp core.sshCommand

/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'core.sshCommand' && git config --local --unset-all 'core.sshCommand' || :

/usr/bin/git config --local --name-only --get-regexp http.https://github.com/.extraheader

/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'http.https://github.com/.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :

/usr/bin/git config --local http.https://github.com/.extraheader AUTHORIZATION: basic ***

Fetching the repository

/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +refs/heads/1.18.x*:refs/remotes/origin/1.18.x* +refs/tags/1.18.x*:refs/tags/1.18.x*

The process '/usr/bin/git' failed with exit code 1

Waiting 17 seconds before trying again

/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +refs/heads/1.18.x*:refs/remotes/origin/1.18.x* +refs/tags/1.18.x*:refs/tags/1.18.x*

The process '/usr/bin/git' failed with exit code 1

Waiting 11 seconds before trying again

/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +refs/heads/1.18.x*:refs/remotes/origin/1.18.x* +refs/tags/1.18.x*:refs/tags/1.18.x*

##[error]The process '/usr/bin/git' failed with exit code 1

Below is first part of action YAML.

name: CMake
on: [push]
env:
Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
BUILD_TYPE: Release
jobs:

build:

# The CMake configure and build commands are platform agnostic and should work equally

# well on Windows or Mac.  You can convert this to a matrix build if you need

# cross-platform coverage.

# See: https://docs.github.com/en/actions/configuring-and-managing-workflows/configuring-a-workflow#configuring-a-build-matrix

runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
  with:
    repository: 'eProsima/Fast-DDS.git'
    ref: '1.18.x'
    path: 'Fast-DDS'
  
- name: Install Fast-DDS dependencies
  run: apt-get -y install gradle default-jdk
  
- name: Fast-DDS Create Build Environment
  # Some projects don't allow in-source building, so create a separate build directory
  # We'll use this as our working directory for all subsequent commands
  run: cmake -E make_directory ${{runner.workspace}}/build-Fast-RDDSTPS
  
- name: Fast-DDS Configure CMake
  # Use a bash shell so we can use the same syntax for environment variable
  # access regardless of the host operating system
  shell: bash
  working-directory: ${{runner.workspace}}/Fast-DDS-build
  # Note the current convention is to use the -S and -B options here to specify source 
  # and build directories, but this is only available with CMake 3.13 and higher.  
  # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
  run: cmake '${{runner.workspace}}/Fast-RTPS' -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DTHIRDPARTY=ON -DBUILD_JAVA=ON
  
- name: Fast-DDS Build and Install
  working-directory: ${{runner.workspace}}/Fast-DDS-build
  shell: bash
  # Execute the build.  You can specify a specific target with "--target <NAME>"
  run: cmake --build . --config $BUILD_TYPE --target install
  
- uses: actions/checkout@v2
  with:
    path: 'ActualRepoName'

...