Dear Maintainer,

This package appears to uninstallable:

```
apt install mercurial-git
Solving dependencies... Error!
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

Unsatisfied dependencies:
 mercurial-git : Depends: python3-dulwich (>= 0.24) but it is not
going to be installed
                 Depends: python3-dulwich (< 0.25) but it is not going
to be installed
Error: Unable to satisfy dependencies. Reached two conflicting assignments:
   1. mercurial-git:amd64=1.2.0-2 is selected for install
   2. mercurial-git:amd64 Depends python3-dulwich (< 0.25)
      but none of the choices are installable:
      [no choices]
```

python3-dulwich version is at 1.2.x, but mercurial-git is requesting >= 0.24 and
< 0.25.

```
apt-cache policy python3-dulwich
python3-dulwich:
  Installed: (none)
  Candidate: 1.2.1-1
  Version table:
     1.2.7-1 100
        100 http://deb.debian.org/debian unstable/main amd64 Packages
     1.2.1-1 500
        500 http://deb.debian.org/debian testing/main amd64 Packages
```

user debian-python@lists.debian.org
usertags 1140463 python3.15
tags 1140463 patch
thanks

Hi!

While rebuilding the python related packages against the Python 3.15rc2 version I ran into this FTBFS [1].

To make hg-git work with a newer dulwich, I had to add upstream patches to support dulwich 1.2 and mercurial 7.2 (17 patches in total)

I also added a patch to handle ChecksumMismatch raised by dulwich >= 1.2.7.

I've applied these fixes in the sandbox [2] to verify that it builds successfully, these should be applied in Debian to get the package back to a healthy state.

Happy hacking,

[1]: https://debusine.debian.net/debian/r-python-python3.15/artifact/4855744/
[2]: https://debusine.debian.net/debian/r-python-python3.15/