Hi,
the test t4058-diff-duplicates reliably dumps core here:
CORE-OF: /home/xxx/yyyyyyy/git/git
DUMPCORE_ARGS:
9975
9975
11
!home!xxx!yyyyyyy!git!git
DUMPCORE_ARGS_END
PROC-9975:
root -> /
cwd -> /home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates
fd/0 -> /dev/null
fd/1 -> /dev/pts/7
fd/2 -> /dev/pts/7
fd/3 -> /dev/pts/7
fd/4 -> /dev/pts/7
fd/5 -> /dev/pts/7
fd/6 -> /dev/pts/7
fd/7 -> /dev/pts/7
fd/8 -> /home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates/.git/index.lock
PROC-9975_END
ENVIRONMENT:
GIT_COMMITTER_NAME=C O Mitter
USER=xxx
GIT_AUTHOR_EMAIL=author@xxxxxxxxxxx
GIT_TEMPLATE_DIR=/home/xxx/yyyyyyy/git/templates/blt
XDG_SEAT=seat0
TAR_OPTIONS=--atime-preserve
GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS=true
_x05=[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]
GIT_EXEC_PATH=/home/xxx/yyyyyyy/git
SSH_AGENT_PID=3796
XDG_SESSION_TYPE=x11
GIT_CEILING_DIRECTORIES=/home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates/..
USER_HOME=/home/xxx
SHLVL=1
LESS=RSX
HOME=/home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates
OLDPWD=/home/xxx/yyyyyyy/git/t
GIT_AUTHOR_DATE=1112354055 +0200
_x35=[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]
DESKTOP_SESSION=lightdm-xsession
ZERO_OID=0000000000000000000000000000000000000000
OID_REGEX=[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
PAGER=cat
GIT_AUTHOR_NAME=A U Thor
DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-qjoVRmyD3o,guid=8cdc53ee0598990a001ad838627364a4
u200c=
COLORTERM=rxvt-xpm
test_prereq=
GNOME_KEYRING_CONTROL=/run/user/1000/keyring
GIT_TEST_MERGE_ALGORITHM=ort
EMPTY_BLOB=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GITPERLLIB=/home/xxx/yyyyyyy/git/perl/build/lib:/home/xxx/yyyyyyy/git/perl/build/lib
LOGNAME=xxx
GIT_ATTR_NOSYSTEM=1
WINDOWID=56623113
_=./t4058-diff-duplicates.sh
GIT_TEST_CHECK_CACHE_TREE=false
XDG_SESSION_CLASS=user
COLORFGBG=15;default
GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
TERM=dumb
XDG_SESSION_ID=2
COLUMNS=80
GIT_TRACE_BARE=1
USER_TERM=rxvt-unicode-256color
GIT_MERGE_VERBOSITY=5
PATH=/home/xxx/yyyyyyy/git/bin-wrappers:/home/xxx/yyyyyyy/git/bin-wrappers:/home/xxx/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
LESSCHARSET=latin1
GDM_LANG=en_US.utf8
GIT_CONFIG_NOSYSTEM=1
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
XDG_RUNTIME_DIR=/run/user/1000
DISPLAY=:0
GIT_DEFAULT_HASH=sha1
LANG=C
LSAN_OPTIONS=fast_unwind_on_malloc=0:strip_path_prefix=/home/xxx/yyyyyyy/git/:abort_on_error=1
GIT_TRACE2_EVENT_NESTING=100
GNUPGHOME=/home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates/gnupg-home-not-used
SHELL=/bin/bash
MALLOC_CHECK_=3
GIT_TEXTDOMAINDIR=/home/xxx/yyyyyyy/git/po/build/locale
EMPTY_TREE=4b825dc642cb6eb9a060e54bf8d69288fbee4904
MALLOC_PERTURB_=165
OSTYPE=linux-gnu
ASAN_OPTIONS=detect_leaks=0:strip_path_prefix=/home/xxx/yyyyyyy/git/:abort_on_error=1
GIT_COMMITTER_EMAIL=committer@xxxxxxxxxxx
PWD=/home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates
SHELL_PATH=/bin/sh
PERL_PATH=/usr/bin/perl
LC_ALL=C
GIT_MERGE_AUTOEDIT=no
LC_NUMERIC=C
TZ=UTC
GIT_COMMITTER_DATE=1112354055 +0200
LF=\n
MANPATH=:/home/xxx/share/man
EDITOR=:
GIT_TEST_FSYNC=0
ENVIRONMENT_END
PID_TRACE:
9975 (git) S /home/xxx/yyyyyyy/git/git merge update
cwd: /home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates
9653 (t4058-diff-dupl) S /bin/sh ./t4058-diff-duplicates.sh -d -v -i
cwd: /home/xxx/yyyyyyy/git/t/trash directory.t4058-diff-duplicates
4932 (bash) S bash
cwd: /home/xxx/yyyyyyy/git/t
4924 (urxvt) S urxvt
cwd: /home/xxx
1 (init) S init [2]
cwd: /
PID_TRACE_END
GDB:
Reading symbols from /home/xxx/yyyyyyy/git/git...
[New LWP 9975]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/home/xxx/yyyyyyy/git/git merge update'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00005629e52f4a00 in traverse_by_cache_tree (info=0x7fff27e7dba8,
info=0x7fff27e7dba8, nr_names=2, nr_entries=4, pos=0)
at unpack-trees.c:807
807 len = ce_namelen(src[0]);
Threads:
Id Target Id Frame
* 1 Thread 0x7f408feb8740 (LWP 9975) 0x00005629e52f4a00 in traverse_by_cache_tree (info=0x7fff27e7dba8, info=0x7fff27e7dba8, nr_names=2, nr_entries=4, pos=0) at unpack-trees.c:807
Stack:
new_ce_len = <optimized out>
len = <optimized out>
rc = <optimized out>
o = 0x7fff27e7e930
tree_ce = 0x5629e596e7d0
ce_len = 240
i = 1
src = {0x5629e594a518, 0x5629e596e7d0, 0x5629e596e7d0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}
d = <optimized out>
src = {<optimized out>, <optimized out>, <optimized out>, <optimized out>, <optimized out>, <optimized out>, <optimized out>, <optimized out>, <optimized out>}
o = <optimized out>
tree_ce = <optimized out>
ce_len = <optimized out>
i = <optimized out>
d = <optimized out>
new_ce_len = <optimized out>
len = <optimized out>
rc = <optimized out>
#0 0x00005629e52f4a00 in traverse_by_cache_tree (info=0x7fff27e7dba8, info=0x7fff27e7dba8, nr_names=2, nr_entries=4, pos=0) at unpack-trees.c:807
#1 traverse_trees_recursive (n=n@entry=2, dirmask=dirmask@entry=3, df_conflicts=df_conflicts@entry=0, names=names@entry=0x7fff27e7df80, info=info@entry=0x7fff27e7e420) at unpack-trees.c:872
#2 0x00005629e52f5668 in unpack_callback (n=<optimized out>, mask=3, dirmask=3, names=0x7fff27e7df80, info=<optimized out>) at unpack-trees.c:1479
#3 0x00005629e52f3162 in traverse_trees (istate=0x5629e541c980 <the_index>, n=n@entry=2, t=t@entry=0x7fff27e7e6f0, info=info@entry=0x7fff27e7e420) at tree-walk.c:532
#4 0x00005629e52f82fa in unpack_trees (len=len@entry=2, t=t@entry=0x7fff27e7e6f0, o=o@entry=0x7fff27e7e930) at unpack-trees.c:1882
#5 0x00005629e523d2ae in checkout_fast_forward (r=0x5629e541caa0 <the_repo>, head=head@entry=0x5629e594be24, remote=remote@entry=0x5629e594be6c, overwrite_ignore=1) at merge.c:94
#6 0x00005629e5135742 in cmd_merge (argc=<optimized out>, argv=<optimized out>, prefix=<optimized out>) at builtin/merge.c:1578
#7 0x00005629e50c921b in run_builtin (argv=0x7fff27e7f9c0, argc=2, p=0x5629e53ead48 <commands+1608>) at git.c:465
#8 handle_builtin (argc=2, argv=0x7fff27e7f9c0) at git.c:719
#9 0x00005629e50ca53d in run_argv (argv=0x7fff27e7f700, argcp=0x7fff27e7f70c) at git.c:786
#10 cmd_main (argc=<optimized out>, argc@entry=3, argv=<optimized out>, argv@entry=0x7fff27e7f9b8) at git.c:917
#11 0x00005629e50c8f03 in main (argc=3, argv=0x7fff27e7f9b8) at common-main.c:56
GDB_END
end
P.S. dumpcore (the tool which produced this trace) is this: https://github.com/raalkml/dumpcore
