git convert shallow clone to full history

When this happens

fatal: --shallow-since is only allowed for fetch
# or
warning: Could not find remote branch ...

Your repository was cloned with --depth 1 (common in CI/CD), so git commands that need full history — like git log, git blame, or git bisect — do not work correctly.

Other causes & fixes

Check if your clone is shallow

git rev-parse --is-shallow-repository    # prints "true" if shallow

Fetch only a limited depth (not full history)

If you do not need the complete history but need more than 1 commit:

git fetch --depth=100

Unshallow a specific remote

git fetch --unshallow origin