python-packman error with HTTPS Error 403 - Forbidden from vault.centos.org on CentOS 7

Symptoms

MultiPHP Manager or EasyApache 4 returns the following error on a CentOS 7 server, and yum makecache fails with 403 errors from vault.centos.org:

CPANEL_ERROR: Error: “/usr/local/cpanel/bin/python-packman” reported error code “1” when it ended: Traceback (most recent call last): ... OSError: [Errno 2] No such file or directory w/ /usr/local/cpanel/bin/packman_get_list_json installed
Often, errors like this can be resolved by running `yum makecache`

Cause

The base repository (https://vault.centos.org/7.9.2009/os/x86_64/) returned a 403 Forbidden, so yum could not download the repository metadata and the python-packman call failed. The 403 was most likely temporary, as it could not be reproduced later. The root cause was not confirmed.

Resolution

1. Access the server using SSH or WHM's Terminal as the root user.

2. Clear and rebuild the yum cache:

   # yum clean all ; yum makecache

3. Confirm the metadata cache is created for all repositories without errors, then retry the operation in WHM.

Note: Adding ip_resolve=4 to /etc/yum.conf did not resolve this issue. If the 403 persists after clearing the cache, see YUM encountered errors outside of EasyApache 4 (IPV6 Outbound Connection).

In the originating ticket, the PHP ELS release (els-php-release and alt-php-els-meta) was already installed, as confirmed by /usr/local/cpanel/scripts/install_tuxcare_els_php. Once the cache rebuilt, the alt-php versions could be selected.

https://cpanel.zendesk.com/agent/tickets/96099367