What is the cause of the letsencrypt certificate installation error?

Question

Debian

On debian 8, I'm trying to install a letsencrypt certificate:

./certbot-auto certonly --manual -d *.site.ru -d site.ru --agree-tos --manual-public-ip-logging-ok --preferred-challenges dns-01 --server https: //acme-v02.api.letsencrypt.org/directory

I get errors during installation:

Setting up cpp (4:4.9.2-2) ...
update-alternatives: error: error creating symbolic link `/lib/cpp.dpkg-tmp': Permission denied
dpkg: error processing package cpp (--configure):
subprocess prevent installed post-installation script returned error exit status 2
dpkg: dependency problems configuration of gcc:
gcc depends on cpp (>= 4:4.9.2-2); however:
Package cpp is not configured yet.
dpkg: error processing package gcc (--configure):
dependency problems - leaving unconfigured
E: Sub-process /usr/bin/dpkg returned an error code (1)

Tell me, how can I solve the problem? All commands are executed as root, so there should be permissions, but in fact they are not.