mcabber fails after password query, when glib2 ~= 2.80

[JudgeGregg]

Hello, and thank you for your work on Mcabber and Loudmouth.

Mcabber fails every time on an up to date Archlinux, right after asking for the jid password. Malloc fails with:

malloc(): unaligned tcache chunk detected
Aborted (core dumped)

Through gdb I managed to get the following trace:

Thread 1 (Thread 0x7ffff6a80980 (LWP 898299) "mcabber"):
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
        tid = <optimized out>
        ret = 0
        pd = <optimized out>
        old_mask = {__val = {140737488342504}}
        ret = <optimized out>
#1  0x00007ffff7b4e393 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007ffff7afd6c8 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
        ret = <optimized out>
#3  0x00007ffff7ae54b8 in __GI_abort () at abort.c:79
        save_stage = 1
        act = {__sigaction_handler = {sa_handler = 0x20, sa_sigaction = 0x20}, sa_mask = {__val = {2883190728961350, 140737488342624, 140737352872275, 140737488343088, 140737353560069, 0, 18446744069414584322, 0, 140737352847635, 256, 1531873955904267008, 140737353560069, 93824993676384, 0, 140737352516757, 1}}, sa_flags = 1431858192, sa_restorer = 0x0}

#4  0x00007ffff7ae6395 in __libc_message_impl (fmt=fmt@entry=0x7ffff7c5e2ea "%s\n") at ../sysdeps/posix/libc_fatal.c:132
        ap = {{gp_offset = 16, fp_offset = 32767, overflow_arg_area = 0x7fffffffcfe0, reg_save_area = 0x7fffffffcf70}}
        fd = 2
        iov = {{iov_base = 0x7ffff7c61988, iov_len = 41}, {iov_base = 0x7ffff7c5e2ec, iov_len = 1}, {iov_base = 0x0, iov_len = 18446744069414584322}, {iov_base = 0x0, iov_len = 140737352847635}, {iov_base = 0x100, iov_len = 1531873955904267008}, {iov_base = 0x7ffff7f73005, iov_len = 93824993676384}, {iov_base = 0x0, iov_len = 140737352516757}}
        iovcnt = <optimized out>
        total = <optimized out>
        cp = <optimized out>
#5  0x00007ffff7b582a7 in malloc_printerr (str=str@entry=0x7ffff7c61988 "malloc(): unaligned tcache chunk detected") at malloc.c:5772
#6  0x00007ffff7b5ca4c in tcache_get_n (ep=<optimized out>, tc_idx=<optimized out>) at malloc.c:3183
        e = <optimized out>
        e = <optimized out>
#7  tcache_get (tc_idx=<optimized out>) at malloc.c:3199
#8  __GI___libc_malloc (bytes=128) at malloc.c:3320
        ar_ptr = <optimized out>
        victim = <optimized out>
        tbytes = <optimized out>
        tc_idx = <optimized out>
        __PRETTY_FUNCTION__ = "__libc_malloc"
#9  0x00007ffff7e763d3 in g_realloc () at /usr/lib/libglib-2.0.so.0
#10 0x00007ffff7e91303 in ??? () at /usr/lib/libglib-2.0.so.0
#11 0x00007ffff7e91371 in g_string_sized_new () at /usr/lib/libglib-2.0.so.0
#12 0x00007ffff7e77555 in g_markup_escape_text () at /usr/lib/libglib-2.0.so.0
#13 0x00007ffff7f69180 in lm_message_node_to_string () at /usr/lib/libloudmouth-1.so.0
#14 0x00007ffff7f65eae in lm_connection_send () at /usr/lib/libloudmouth-1.so.0
#15 0x00007ffff7f67120 in ??? () at /usr/lib/libloudmouth-1.so.0
#16 0x00007ffff7f6f44f in ??? () at /usr/lib/libloudmouth-1.so.0
#17 0x00007ffff7e6bf69 in ??? () at /usr/lib/libglib-2.0.so.0
#18 0x00007ffff7eca3a7 in ??? () at /usr/lib/libglib-2.0.so.0
#19 0x00007ffff7e6a162 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#20 0x00005555555626ca in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/mcabber/mcabber-1.1.2/mcabber/main.c:558
        mc_source = 0x5555556b8330
        mc_pollfd = 0x5555556b8390
        configFile = <optimized out>
        optstring = <optimized out>
        optval = <optimized out>
        optval2 = <optimized out>
        ret = <optimized out>
Not confirmed.

Versions:
Name : mcabber
Version : 1.1.2-2

Name : loudmouth
Version : 1.5.4-1

Name : glib2
Version : 2.80.0-2

It works perfectly fine on an Ubuntu, with an older version of the glib2: Version: 2.64.6-1~ubuntu20.04.6

It can be reproduced on a fresh Arch install, via docker or podman for example.

Edit:
Apparently the last glib2 version working is:
glib2-2.74.6-1-x86_64.pkg.tar.zst

Switching to glib2-2.76.5-2-x86_64.pkg.tar.zst makes mcabber crashes right after the password query.
https://archive.archlinux.org/packages/g/glib2/