SIGSEGV Error Occurs When Attempting to Unbundle Without Initializing Git Repository.

#### Steps to Reproduce I attempted to unbundle a pack but forgot to execute `git init` beforehand.

#### Expected Behavior An error message should have been displayed, reminding me to run `git init`.

#### Actual Behavior The process unexpectedly terminated with a SIGSEGV (Address boundary error).

#### Difference Between Expected and Actual Behavior Instead of gracefully exiting, the process terminated abruptly.

#### System Info
- Git Version: 2.46.0
- CPU: x86_64
- No commit associated with this build
- Size of `long`: 8 bytes
- Size of `size_t`: 8 bytes
- Shell Path: /bin/sh
- libcurl Version: 8.9.0
- OpenSSL Version: 3.3.1 (4 Jun 2024)
- zlib Version: 1.3.1
- uname: Linux 6.10.3-arch1-2 #1 SMP PREEMPT_DYNAMIC Tue, 06 Aug 2024 07:21:19 
+0000 x86_64
- Compiler Info: GNU Compiler Collection (GCC) 14.1
- libc Version: glibc 2.40
- Interactive Shell: /usr/bin/fish