Git fails to describe project in build server

I'm trying to `snapcraft remote-build` the Charmcraft snap, which calculates the version doing `git describe --tags --dirty`.

However, that command fails on the servers.

FTR, the project uploaded by Snapcraft has the proper tags in it, this is the output I get if I tweak the project to do `git log`:

```
commit b22fcdba3b894004468abfbf45caa54d93fbf7d0 (HEAD -> refs/heads/release-2.1, tag: refs/tags/2.1.0, tag: refs/tags/2.1, refs/remotes/upstream/main, refs/heads/main)
```

(full output of the command: https://pastebin.ubuntu.com/p/8GXRCJTR3K/)

The problem is that Git is failing with:

```
fatal: detected dubious ownership in repository at '/build/snapcraft-charmcraft-f3e050ba9add253d3c37d743f9b09089/parts/charmcraft/src'
To add an exception for this directory, call:

    git config --global --add safe.directory /build/snapcraft-charmcraft-f3e050ba9add253d3c37d743f9b09089/parts/charmcraft/src
```

Which is weird, because everything looks owned by `root`: the following is the result of running `id` instead of `git` in the server:

    uid=0(root) gid=0(root) groups=0(root)

...and attached in this report is the whole output of `find /build -ls`.

The Git version in the servers is:

```
git version 2.25.1
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
```

Thanks!