Can't checkout repository with checkout@v2

I use checkout@v2 to checkout the repository in a workflow, and it went well. However all of a sudden, it starts to fail:

2021-06-17T02:43:50.2664954Z ##[group]Run actions/Checkout@v2
2021-06-17T02:43:50.2665573Z with:
2021-06-17T02:43:50.2666047Z   repository: ${GIT_USER}/{GIT_REPO_NAME}
2021-06-17T02:43:50.2666988Z   token: ***
2021-06-17T02:43:50.2667408Z   ssh-strict: true
2021-06-17T02:43:50.2667937Z   persist-credentials: true
2021-06-17T02:43:50.2668428Z   clean: true
2021-06-17T02:43:50.2668854Z   fetch-depth: 1
2021-06-17T02:43:50.2669289Z   lfs: false
2021-06-17T02:43:50.2669705Z   submodules: false
2021-06-17T02:43:50.2670144Z ##[endgroup]
2021-06-17T02:43:51.1242808Z Syncing repository: ${GIT_USER}/{GIT_REPO_NAME}
2021-06-17T02:43:51.1243779Z ##[group]Getting Git version info
2021-06-17T02:43:51.1244947Z Working directory is '/home/runner/work/${GIT_REPO_NAME}/${GIT_REPO_NAME}'
2021-06-17T02:43:51.1245840Z [command]/usr/bin/git version
2021-06-17T02:43:51.1246431Z git version 2.31.1
2021-06-17T02:43:51.1247548Z ##[endgroup]
2021-06-17T02:43:51.1248433Z Deleting the contents of '/home/runner/work/${GIT_REPO_NAME}/${GIT_REPO_NAME}'
2021-06-17T02:43:51.1249841Z ##[group]Initializing the repository
2021-06-17T02:43:51.1250624Z [command]/usr/bin/git init /home/runner/work/${GIT_REPO_NAME}/${GIT_REPO_NAME}
2021-06-17T02:43:51.1251683Z hint: Using 'master' as the name for the initial branch. This default branch name
2021-06-17T02:43:51.1252591Z hint: is subject to change. To configure the initial branch name to use in all
2021-06-17T02:43:51.1253630Z hint: of your new repositories, which will suppress this warning, call:
2021-06-17T02:43:51.1254345Z hint: 
2021-06-17T02:43:51.1255168Z hint:  git config --global init.defaultBranch <name>
2021-06-17T02:43:51.1255831Z hint: 
2021-06-17T02:43:51.1256657Z hint: Names commonly chosen instead of 'master' are 'main', 'trunk' and
2021-06-17T02:43:51.1257711Z hint: 'development'. The just-created branch can be renamed via this command:
2021-06-17T02:43:51.1258430Z hint: 
2021-06-17T02:43:51.1259080Z hint:  git branch -m <name>
2021-06-17T02:43:51.1259864Z Initialized empty Git repository in /home/runner/work/${GIT_REPO_NAME}/${GIT_REPO_NAME}/.git/
2021-06-17T02:43:51.1260852Z [command]/usr/bin/git remote add origin https://github.com/${GIT_USER}/{GIT_REPO_NAME}
2021-06-17T02:43:51.1261625Z ##[endgroup]
2021-06-17T02:43:51.1262304Z ##[group]Disabling automatic garbage collection
2021-06-17T02:43:51.1263209Z [command]/usr/bin/git config --local gc.auto 0
2021-06-17T02:43:51.1263831Z ##[endgroup]
2021-06-17T02:43:51.1265588Z ##[group]Setting up auth
2021-06-17T02:43:51.1266808Z [command]/usr/bin/git config --local --name-only --get-regexp core\.sshCommand
2021-06-17T02:43:51.1268328Z [command]/usr/bin/git submodule foreach --recursive git config --local --name-only --get-regexp 'core\.sshCommand' && git config --local --unset-all 'core.sshCommand' || :
2021-06-17T02:43:51.1269846Z [command]/usr/bin/git config --local --name-only --get-regexp http\.https\:\/\/github\.com\/\.extraheader
2021-06-17T02:43:51.1271675Z [command]/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' || :
2021-06-17T02:43:51.1273487Z [command]/usr/bin/git config --local http.https://github.com/.extraheader AUTHORIZATION: basic ***
2021-06-17T02:43:51.1274405Z ##[endgroup]
2021-06-17T02:43:51.1275039Z ##[group]Fetching the repository
2021-06-17T02:43:51.1277200Z [command]/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +3efa47092fe2a47ad48e2f03e59a33f2abccc888:refs/remotes/origin/gitspace-bodong-autold-bits-test
2021-06-17T02:43:51.1278752Z remote: Repository not found.
2021-06-17T02:43:51.1283295Z ##[error]fatal: repository 'https://github.com/${GIT_USER}/{GIT_REPO_NAME}/' not found
2021-06-17T02:43:51.1293821Z The process '/usr/bin/git' failed with exit code 128
2021-06-17T02:43:51.1294638Z Waiting 18 seconds before trying again
2021-06-17T02:44:08.6992989Z [command]/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +3efa47092fe2a47ad48e2f03e59a33f2abccc888:refs/remotes/origin/gitspace-bodong-autold-bits-test
2021-06-17T02:44:08.8011832Z remote: Repository not found.
2021-06-17T02:44:08.8015605Z ##[error]fatal: repository 'https://github.com/${GIT_USER}/{GIT_REPO_NAME}/' not found
2021-06-17T02:44:08.8022605Z The process '/usr/bin/git' failed with exit code 128
2021-06-17T02:44:08.8024914Z Waiting 12 seconds before trying again
2021-06-17T02:44:20.8066487Z [command]/usr/bin/git -c protocol.version=2 fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 origin +3efa47092fe2a47ad48e2f03e59a33f2abccc888:refs/remotes/origin/gitspace-bodong-autold-bits-test
2021-06-17T02:44:20.8937604Z remote: Repository not found.
2021-06-17T02:44:20.8966351Z ##[error]fatal: repository 'https://github.com/${GIT_USER}/{GIT_REPO_NAME}/' not found
2021-06-17T02:44:20.8977052Z ##[error]The process '/usr/bin/git' failed with exit code 128

The usage of the checkout action is simple:

    steps:
      - name: Check out source repository
        uses: actions/checkout@v2

Any idea what is going on? Any suggestions for fixing this?

Well, it recovered itself.