Today I encountered with "Unmet Dependencies" issue while trying to install curl on my Debian 12 system. I thought it would be a quick install, but I ran into the following error:
The following packages have unmet dependencies: curl : Depends: libcurl4 (= 7.88.1-10+deb12u7) but 8.10.1-1~bpo12+1 is to be installed E: Unable to correct problems, you have held broken packages.
After some digging, I realized that this error occurs because of a version mismatch between libcurl4 and curl. The package manager tried to install an incompatible version of libcurl4, leading to broken dependencies.
This error occurred after I upgraded Curl to version 8.10 from the backports repository, then removed it and tried to install it from the stable repository.
Fix "Unmet Dependencies" Error When Installing Curl in Debian
1. Remove libcurl4:
First, I removed the problematic libcurl4 package with this command:
sudo apt remove libcurl4
2. Reinstall Curl:
Then, I installed curl again, which completed without any further issues:
sudo apt install curl
After following these steps, curl installed successfully, and everything seemed fine… until I ran into another problem.
Important Warning: Apache May Break
After removing the libcurl4 package, my Apache web server stopped working and started returning a 502 Bad Gateway error. This happened because the removal of libcurl4 caused a break in some dependencies that Apache relies on.
Be cautious when removing libcurl4, especially if you're running web services like Apache. In my case, after removing this package, I had to completely reconfigure my Apache2 settings to get the server back online. Unfortunately, reinstalling libcurl4 didn’t fix the problem right away, and I had to do some manual intervention.
Final Thoughts
If you're facing the same issue, try the fix above, but be careful. If you're running services that depend on libcurl4, removing it might cause them to stop working.
Updating core system libraries from the backports repository can sometimes lead to unexpected issues. Backports repositories are designed to provide newer versions of packages that are not yet available in the stable Debian release. Newer versions of core libraries can sometimes introduce dependency conflicts. Other packages on your system might rely on specific versions of these libraries, and upgrading them can break these dependencies. This can lead to a cascade of issues that are difficult to diagnose and fix.
So it is not always recommended to install core system libraries from Backports repository.
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2 comments
Eh? This article is astonishingly nonsensical.
The real issue here is that you misconfigured your system. The described error does not happen on a plain Debian 12 system and neither with the default configuration of backports.
So, explaining how you broke it and how to fix the underlying breakage would be more helpful than blaming Debian.
Yes, you’re totally right. I will update the guide with the root cause of this error when I have time.