versiongetter: use a permissive AlternatesFS with git-go

[database64128]

versiongetter does not work in Arch Linux's package build environment, because repo.Log(&git.LogOptions{From: head.Hash()}) somehow returns plumbing.ErrObjectNotFound.

It might take some time before I can find out the root cause and submit a fix, so here's the preliminary change that wraps errors with additional context.

Update: See the added comment in code.

Fixes #3409.

[aler9]

Hello, the error message you've reported is usually triggered when repositories are pulled with --depth=1:

git clone --depth=1 https://github.com/bluenviron/mediamtx

When repositories are cloned in this way, the tag list is not available:

git tag

(this returns an empty list)

and the server is unable to get its tag.

In my opinion there are two ways to solve the issue:

1. we can find an alternative way to get the server tag, that is compatible with --depth=1
2. you have to alter the Arch Linux package in order to download the full repository.

I like the first approach better - try looking around.

[database64128]

you have to alter the Arch Linux package in order to download the full repository.

AFAIK this is not possible. The makepkg program first clones the remote repository into a local mirror repository, and then clones the local mirror repository into a separate package src repository, and switches to a new makepkg branch, where the actual build script runs. There's no way to change how the src repository is set up.

Mirror repo config (mediamtx/config):

[core]
    repositoryformatversion = 0
    filemode = true
    bare = true
[remote "origin"]
    url = https://github.com/bluenviron/mediamtx.git
    fetch = +refs/*:refs/*
    mirror = true

src repo config (src/mediamtx/.git/config):

[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
[remote "origin"]
    url = /home/database64128/repos/aur/mediamtx/mediamtx
    fetch = +refs/heads/*:refs/remotes/origin/*
[branch "main"]
    remote = origin
    merge = refs/heads/main

Inside the src repo, git log correctly shows the latest commit/tag:

commit 32d3fc55ccc631ad125462063b7bf387595209fe (HEAD -> makepkg, tag: v1.9.2)

[database64128]

When repositories are cloned in this way, the tag list is not available:

The src repo is not cloned with --depth=1. The full tag list and commit history are available via git tag and git log.

repo.Tags() is actually able to iterate over all tags. repo.Log(&git.LogOptions{From: head.Hash()}) does not work and repo.Log(&git.LogOptions{All: true}) returns an iterator that immediately gives EOF.

[database64128]

Likely the same issue as mentioned in go-git/go-git#1125 and go-git/go-git#1002. I'll update this PR once I get things working.

[database64128]

Hi, I have pushed the fix to the branch and updated the PR title. It's now ready for review.

[aler9]

I tested it on both Linux and Windows and it seems to be working. This has been merged.
Thanks for the patch and thanks for maintaining the Arch Linux package.

[github-actions]

This issue is mentioned in release v1.9.3 🚀
Check out the entire changelog by clicking here