install in ubuntu 24.04 gives "Permission denied" warning.

[pseudomonas]

This might be my system being set up weird but:

When sudo apt install -ing the .deb, I get the ominous-sounding N: Download is performed unsandboxed as root, as file '/home/myuser/bin/prelockd/deb/package.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied)

I don't know how much of a problem this is, but a bit of web searching suggests mv ./deb/package.deb /tmp && sudo apt install /tmp/package.deb which removes the warning. (there may well be a cleaner and/or safer way to do it)

[hakavlad]

just ignore it. It's just warning, not a err.

---

This is a legitimate permission issue, not a sign of system misconfiguration—it's actually a security feature working as intended.

What's happening

The _apt user (a dedicated unprivileged account) normally handles downloading and verifying packages for security reasons. When apt tries to access your .deb file in /home/myuser/bin/prelockd/deb/, it can't read it because:

• The file is in your home directory, which typically has restrictive permissions
• The _apt user doesn't have read access to /home/myuser/

So apt falls back to running the entire operation as root (unsandboxed), which defeats the security sandbox. This works, but it's not ideal.

Better solutions than moving to /tmp

Your mv workaround works because /tmp is world-readable, but here are cleaner options:

Option 1: Fix the permissions (simplest)

chmod 644 /home/myuser/bin/prelockd/deb/package.deb
sudo apt install /home/myuser/bin/prelockd/deb/package.deb

This lets _apt read the file while keeping it in place.

Option 2: Use a world-readable directory
Instead of storing .deb files in your home directory, keep them in /opt or another system directory where _apt can naturally access them.

Option 3: Install directly from stdin (elegant but less common)

sudo apt install < /home/myuser/bin/prelockd/deb/package.deb

This pipes the file directly to apt, bypassing the permission check entirely.

The security angle

The warning exists because running apt unsandboxed as root is riskier—if there's a vulnerability in apt's dependency resolution or package handling, it runs with full system privileges. By fixing permissions, you let apt stay sandboxed, which is the safer approach.

Option 1 (chmod) is probably your best bet for a one-liner that keeps things clean and maintains security.

[hakavlad]

you can just ignore it. The package installs fine, and it works.

It's just a warning, not an error. apt is simply telling you that it couldn't use the sandbox (sandboxed mode) and had to run itself as root without restrictions. But the installation completes successfully.

There's really no problem if:

• You trust this .deb file
• It's your machine, not a shared/server system
• You don't care too much about maximum security

Many people just ignore this warning and install packages the way you did originally. The warning exists, but it's not critical for most cases.

If you want to get rid of the warning — use one of the methods I described above. But if it doesn't bother you much, just leave it as is.