I managed to crash git with ctrl+c. I suspect this is because I caught it in malloc, which aborted. If that's the case then it might not be interesting for git developers, but I include the bug report here for completeness.
I performed a clone, using an existing clone as a reference. I then pressed ctrl+c a second or so later:
$ git clone --reference linus https://github.com/shenki/linux shenki ^Cgit: malloc.c:2517: sysmalloc: Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0)' failed. Aborted (core dumped)
There was a directory created, but I removed it before thinking it might be interesting to keep around.
Unfortunately systemd ate the core dump, as I can't find it on my system.
coredumpctl dump 1916302
[sudo] password for joel:
PID: 1916302 (git)
UID: 1007 (joel)
GID: 1007 (joel)
Signal: 6 (ABRT)
Timestamp: Mon 2022-04-04 20:23:11 EDT (2h 22min ago)
Command Line: git clone --reference linus
https://github.com/shenki/linux shenki
Executable: /usr/bin/git
Control Group: /user.slice/user-1007.slice/session-849.scope
Unit: session-849.scope
Slice: user-1007.slice
Session: 849
Owner UID: 1007 (joel)
Boot ID: ad25355486094e3d986595692797a966
Machine ID: af0681c1d3194b8a9f9e1dd4c056ec09
Hostname: kal1
Storage: none
Message: Process 1916302 (git) of user 1007 dumped core.
Coredump entry has no core attached (neither internally in the journal
nor externally on disk).[System Info] git version: git version 2.31.1 cpu: x86_64 no commit associated with this build sizeof-long: 8 sizeof-size_t: 8 shell-path: /bin/sh uname: Linux 5.14.0-1.6.1.el9.x86_64 #1 SMP Mon Oct 4 14:14:47 EDT 2021 x86_64 compiler info: gnuc: 11.2 libc info: glibc: 2.34 $SHELL (typically, interactive shell): /bin/bash