Re: [Buildroot] [PATCH] package/pkg-generic: add support for uninstalling packages

[Andreas Ziegler <br025@umbiko.net>]

Hi Thomas, Shubham, ALL,

On 2026-03-17 10:08, Thomas Petazzoni wrote:
> 
> Hello,
> 
> On Tue, Mar 17, 2026 at 01:41:25PM +0530, Shubham Chakraborty wrote:
> 
>> I didn't consider reverse dependencies. The scenario you described
>> (uninstalling openssl breaking ntp) is a
>> serious problem that makes the current implementation unsafe.
>> 
>> I see a few potential approaches to address this:
>> 
>>  1. Add dependency checking that refuses to uninstall if reverse
>> dependencies exist (similar to package managers like apt/dnf)
> 
> This would make the feature useless for a significant number of
> packages I'd say.

In most cases, exactly these reverse dependencies make removal of the 
package desirable. Testing with and without sometimes needs manual 
intervention. Also I prefer clearing up the mess after testing to doing 
a full rebuild: it's less time consuming.

>>  2. Implement cascade uninstall (uninstall the package and all its 
>> reverse
>> dependencies)
> 
> This would probably be the logical thing, I guess?
> 

Nice to have, but is it worth the effort? This is not a tool for 
everyday use, and most people will know what they are doing.

>>  4. Simply document this as a "use at your own risk" feature for 
>> advanced
>> debugging scenarios
>> 
>> I wanted to ask: would any of these approaches be acceptable for 
>> Buildroot?
>> Or is the fundamental issue that without proper
>> dependency tracking during uninstall, this feature is too dangerous to
>> include regardless of warnings/checks?
> 
> This has so far been the project's opinion on this topic. But nothing
> is set in stone forever, so we can always revisit/rediscuss things.

I used to delete files manually, until I discovered the central 
packages-file-list*.txt files, and have been using a similar Python 
script for a few years. Shubham's approach to use the package based 
lists is better.

Including the script as a build target is optional.

> Thomas
> --
> Thomas Petazzoni, co-owner and CEO, Bootlin
> Embedded Linux and Kernel engineering and training
> https://bootlin.com

Kind regards,
Andreas
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