New review comment by pudiva on void-packages repository

https://github.com/void-linux/void-packages/pull/32162#discussion_r677085127

Comment:
> At worst, echo $version > somefile and patch cmake to read from that instead.

Unfortunately this is how **build/version.sh** generates a new **git_version.h** file:

```sh
new_version_h="\
#define BUILD_GIT_VERSION_NUMBER ${git_revision}
#define BUILD_GIT_VERSION_STRING \"${git_version_str}\"
#define TAGGED_RELEASE ${tagged_release}
#define INSTALLER_VERSION \"${installer_version}\"
#define RESOURCE_BASE_VERSION ${resource_version}"
```

I'm concerned with the `BUILD_GIT_VERSION_NUMBER` macro, that is set to `$git_revision`, that is defined as:

```sh
last_svn_revision=6962
last_svn_hash="16cd907fe7482cb54a7374cd28b8501f138116be"

git_revision=$(expr $last_svn_revision + $(git log --pretty=oneline $last_svn_hash..HEAD 2>/dev/null | wc -l))
```

which basically counts the number of commits since  `$last_svn_hash` and adds `$last_svn_revision`.

Now there are three options:

1. fetch with git
2. generate **git_version.h** on `pre_configure()`
   2.1. using hardcoded values manually extracted from git by the pkg maintainer (me???) on every update
   2.2. using the template's `$version` and never updating the other values

I did a little grepping but gave up following where the variable is ultimately used, so I'm not sure how important it is :woman_shrugging: 

To be honest, I'd rather go with what the maintainer supports, which is building from git, instead of creating more pkg maintenance overhead trying to build from the release tarballs that they'd have removed if they could:

> There are no release tarballs. “Source Code (zip)” and “Source Code (tar.gz)” listed on the release page are just automatically generated archives of the source, _without the `.git`-folder_ thus making them useless for regular building.Afaik GitHub doesn't allow to disable those.

https://github.com/wangqr/Aegisub/issues/116#issuecomment-886105613

... and I'm not even sure this is the only problem with the tarballs.

What do you think? :sparkles: :sparkles: :sparkles: