How can I find out why I can't install packages on ALT Linux?

Question

linux

I uploaded the image to a USB flash drive, started in Live mode, and tried to install some package:

[[email protected] ~]$ sudo apt-get update
Чтение списков пакетов... Завершено
Построение дерева зависимостей... Завершено
[[email protected] ~]$ sudo apt-get install nmap
Чтение списков пакетов... Завершено
Построение дерева зависимостей... Завершено
E: Невозможно найти пакет nmap
[[email protected] ~]$

Answer 1

nmap is in the repositories. The problem turned out to be that these repositories were commented out in the Live distribution.

Answer 2

In the connected repositories there is no such package - nmap.
What repositories do you have enabled? Their settings are stored in /etc/apt/sources.list or sources.list.d
. They are enabled through Enabled = 1 in the corresponding files.
apt-cache search nmap shows what?

Answer 3

There they have a graphical settings utility. In live mode, repositories seem to be disabled. Previously, I turned them on manually in this mode.