Alien (Fakeroot)

According to 'man fakeroot', fakeroot does not "gives root permissions". It only "runs a command in an environment wherein it appears to have root privileges for file manipulation".

Perfect can we convert tar.gz to deb without alien ?

Which tar.gz are you referring to?

https://github.com/Eloston/ungoogled-chromium/releases/tag/95.0.4638.69-1

here you can see .tar.gz file source code I want to make .deb file myself in deb package from their source code.

That's not what alien is for. Alien is for converting binary packages (not source code) in other distro's formats to .deb packages.

If you want to compile ungoogled-chromium from source, you need to follow the directions here: https://github.com/Eloston/ungoogled-chromium/blob/master/docs/building.md. I have done it before, and I should warn you that it takes a really, really long time. Over a day for me. Hopefully your computer is more powerful than mine.

EDIT: To build a deb package, follow these instructions (at the bottom): https://github.com/ungoogled-software/ungoogled-chromium-debian/blob/unified/.github/README.md

Ohk I got your point now.

I found useful resources now for making deb from source code which is something I should do rather than from binary packages.

Thank you for your help I will try soon

This sounds like a big waste of time and over-engineered, it would be way faster and more simple to just run Ungoogled Chromium inside Firejail, not a long ago someone here mentioned using Firejail as well.

I'm not sure what the relevance of Firejail is here. I think OP wants to compile ungoogled-chromium from source. I provided a link to the instructions for doing that.

yes I understand @JC8 provided weird comments obvious if we want to sure binary is complied correct so we do that from source what is wrong in that :D

max 2 Days waste of time but good results which we own complied...

Installing ungoogled chromium from FlatPak is risky as FlatPak contains non free softwares right ?

Flatpak: Available in the Flathub repo as com.github.Eloston.UngoogledChromium
GNU Guix: Available as ungoogled-chromium
NixOS/nixpkgs: Available as ungoogled-chromium

in github repo

Installing ungoogled-chromium from Flathub is safe. It is free software. But I was just noting that Flathub has a lot of proprietary software, so if you install anything else from there you should be careful and check the license.