Steps to reproduce:

1. PHP 8.2.7; Phorge at bab99707405585911ca0e07d52d7117acd08fbcc
2. Check that http://phorge.localhost/config/edit/repository.default-local-path/ is set to default /var/repo/
3. Make sure that /var/repo/ exists locally with permissions that only the root user can access that directory and not Phorge
4. As a Phorge admin, go to Diffusion at http://phorge.localhost/diffusion/
5. Select Create Repository in upper right corner to go to http://phorge.localhost/diffusion/edit/form/default/
6. Select "Create Git Repository" to go to http://phorge.localhost/diffusion/edit/form/default/?vcs=git
7. On the Create Repository page, in the Name field, enter gitRepo
8. Select the Create Repository button
9. Go to http://phorge.localhost/diffusion/17/manage/
10. Select Activate Repository in the left panel (while no directory exists for this code repository)
11. Look at the Working Copy Status section on http://phorge.localhost/diffusion/17/manage/

Actual outcome:

Initialization Error
Pull of 'R17' failed: strlen(): Passing null to parameter #1 ($string) of type string is deprecated

Raw Error
Error updating working copy: strlen(): Passing null to parameter #1 ($string) of type string is deprecated

Expected outcome:

Initialization Error
Pull of 'R17' failed: Command failed with error #128! COMMAND git init --bare -- /var/repo/17 STDOUT (empty) STDERR fatal: cannot mkdir /var/repo/17: Permission denied

Raw Error
Error updating working copy: Command failed with error #128!
COMMAND
git init --bare -- /var/repo/17

STDOUT
(empty)

STDERR
fatal: cannot mkdir /var/repo/17: Permission denied

Other comments:
No stacktrace as nothing is in the error log, thus I temporarily edited src/applications/repository/management/PhabricatorRepositoryManagementUpdateWorkflow.php to print $ex->getExceptionTrace()) in the UI to find the line to fix.