When / does not have the proper permissions, many things can fail in the system, package utilities or even the system itself. The most logical thing would be to reinstall and start from scratch, but in cases where this is not possible, we can try one last trick. Dump the permissions from a healthy system and restore them.
Obtain the permissions from the healthy system:
getfacl -R / > Good.acl
Restore:
setfacl --restore=Good.acl