[Improvement] check if repository is shallow before other operations

[BinToss]

Requires:

• Support for shallow repositories libgit2/libgit2#3058
• Shallow clone support libgit2/libgit2sharp#229

If a repository is shallow, halting and throwing a detailed exception would clarify the reason for the NullReferenceException reported in #2734

Detailed Description

Context

Throwing an informative exception message is more useful than an unhandled NullReferenceException.

Possible Implementation

GitVersion should query git rev-parse --is-shallow-repository (or test for ".git/shallow" file with very old Git clients) and then throw an exception if the operation returns "true".

ref: https://stackoverflow.com/qestions/37531605/how-to-test-if-git-repository-is-shallow

[asbjornu]

Great idea! If LibGit2Sharp exposes this information directly, that would be the best solution as we would like to avoid relying on the git command line or the existence of files or directories on disk.

[BinToss]

libgit2/libgit2#3058
Looks like LibGit2Sharp's underlying library is unable to parse shallow repositories at all. So, LibGit2 would need to support shallow repositories before it can parse whether a repository is shallow or not.

[asbjornu]

However unfortunate, that does not come as a surprise. 😕

[stale]

This issue has been automatically marked as stale because it has not had recent activity. After 30 days from now, it will be closed if no further activity occurs. Thank you for your contributions.

[BinToss]

As of May 9, 2023, LibGit2 supports shallow repositories. However, LibGit2Sharp is still blocking.

[BinToss]

btw this issue was automatically closed due to inactivity despite not having been resolved.