The script uses set -e combined with git stash push --keep-index. If dotnet format exits non-zero (e.g., build failure, restore issue, or tooling error), set -e aborts the script immediately. While the EXIT trap will still fire and attempt to restore the stash, the script never reaches the diff check or the user-facing error message — developers get a silent/cryptic failure with output redirected to /dev/null 2>&1, making it impossible to diagnose why the hook failed. Combined with 2>&1 > /dev/null, real formatter errors are completely swallowed.

The --exclude argument ./**/*OptionsSetup.cs is unquoted, so bash expands it before passing to dotnet format. Without shopt -s globstar, ** behaves as a single * and won't recurse; with globstar enabled it expands to a list of paths that are passed as multiple arguments. Either way, the behavior diverges from CI (which presumably passes the literal pattern) and the exclude may not match the intended files, causing the hook to fail commits over files that CI ignores.

git stash push --keep-index stashes unstaged changes, leaving staged changes in the working tree — but the working tree still contains all other tracked files. dotnet format then scans the entire solution and may reformat files that the developer didn't touch (e.g., pre-existing formatting drift on unrelated files). The hook will then fail the commit even though the staged diff is clean, blocking commits for issues outside the developer's change scope.