Push results in message about HEAD ref not existing

Running the following command:

$ git push git@ConnectorHost:gD1/repo8 main

results in:

Counting objects: 3, done.
Writing objects: 100% (3/3), 226 bytes \| 0 bytes/s, done.
Total 3 (delta 0), reused 0 (delta 0)
remote: HEAD ref is "refs/heads/master", but this ref does not exist.
remote: Consider asking the admin for repo "gD1/repo8.git"
remote: to set its default branch to a valid ref so that
remote: "git clone" and "git checkout" can check out
remote: without specifying a branch name.
To git@xx.x.xx.xxx:repo/grepo1
 * [new branch]      main -> main

To resolve this issue, do one of the following:

• Edit the repo spec to specify refs/heads/main as the default branch to clone from. This is required for any project not using the refs/heads/master default branch. For details, see Specify a default branch.

• Run the following special command to set the default branch to refs/heads/main:

  $ git clone git@ConnectorHost:@defaultbranch:gD1/repo8=refs/heads/main

  This results in the following output:

  git clone git@ConnectorHost:@defaultbranch:gD1/repo8=refs/heads/main
  Cloning into 'main'...
  repo='gD1/repo8', old DefaultBranch='', new DefaultBranch='refs/heads/main'
  fatal: Could not read from remote repository.
  Please make sure you have the correct access rights and the repository exists.

  Note

  Because the special command is not standard Git syntax, Git cannot parse it and the command terminates with:

  Fatal: Could not read from remote repository.

  You can also run @defaultbranch:gD1/repo8 to show the default branch and @defaultbranch:gD1/repo8= to clear the default branch.