Cinnamon Runtime Issues

[eskilop]

Compilation of gnome-extra/cinnamon succeeds, but upon login cinnamon crashes and goes in fallback mode. My display manager and Xorg logs are clean, but I can see the following errors in dmesg:

[42943.599606] elogind-daemon[2333]: New session 7 of user eskilop.
[42944.470634] traps: cinnamon[18363] general protection fault ip:7f54f9b609f0 sp:7ffca9d251c0 error:0 in libcjs.so.0.0.0[7f54f9b2c000+83000]
[42952.104851] pulseaudio[18234]: segfault at 55823cd22320 ip 00007f569312d8c7 sp 00007ffec5d65490 error 4 in libICE.so.6.3.0[7f5693127000+10000]
[42952.104865] Code: 1f 40 00 41 54 48 8d 35 35 9c 00 00 31 c0 55 48 89 fd 48 83 ec 08 8b 57 1c bf 02 00 00 00 e8 e0 ad ff ff 48 8b 45 00 48 89 ef <ff> 90 80 00 00 00 41 89 c4 bf 03 00 00 00 48 89 ea 48 8d 35 74 9b
[42952.118580] elogind-daemon[2333]: Removed session 7.
[44880.877692] elogind-daemon[2333]: New session 10 of user eskilop.
[44910.880482] cinnamon-sessio[8327]: segfault at 0 ip 00007fa6106052d9 sp 00007fff4b33b650 error 4 in libgobject-2.0.so.0.7000.4[7fa6105d8000+3d000]
[44910.880493] Code: c1 02 00 89 d8 48 8b 04 c2 48 89 85 e8 fe ff ff 48 85 c0 0f 84 30 02 00 00 48 8b 70 08 49 89 c7 48 8b 85 d0 fe ff ff 48 8b 00 <48> 8b 38 e8 5f 71 00 00 85 c0 0f 84 0f 02 00 00 44 8b 8d c8 fe ff
[44910.893580] elogind-daemon[2333]: Removed session 10.
[45010.520755] elogind-daemon[2333]: New session 11 of user eskilop.
[45011.649510] cinnamon[13199]: segfault at 28 ip 00007f8aaf1f9420 sp 00007fffff8b93d8 error 4 in libst.so[7f8aaf1c4000+65000]
[45011.649518] Code: ff 85 c0 0f 84 76 ff ff ff e8 fc f2 ff ff 48 89 c6 48 89 ef e8 31 c8 fc ff e9 61 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 <48> 8b 47 28 48 8b 40 08 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 66
[45018.222895] elogind-daemon[2333]: Removed session 11.

So, thanks to @Alessandro-Barbieri for pointing me in the right direction, I've found that the following overrides:

gnome-extra/cinnamon		*FLAGS-=-flto*
gnome-extra/cinnamon-session	*FLAGS-=-flto*
gnome-extra/cjs			*FLAGS-=-flto*
gnome-base/gvfs			*FLAGS-=-flto*

media-sound/pulseaudio		*FLAGS-=-flto*

Are needed to solve the segfaults, and get cinnamon to launch successfully. Although, There is still a segfault when attempting to change the network settings from the control panel. I tried running it in the command line (cinnamon-settings network) and I got these interesting outputs:

/usr/lib/python3.9/site-packages/gi/overrides/Gio.py:42: Warning: invalid unclassed pointer in cast to 'NMACertChooserButton'
/usr/lib/python3.9/site-packages/gi/overrides/Gio.py:42: Warning: g_type_instance_get_private: assertion 'instance != NULL && instance->g_class != NULL' failed

And this in the dmesg:

[17625.392362] cinnamon-settin[5511]: segfault at 20 ip 00007f7c500ba99e sp 00007fffc79176e0 error 4 in libnma.so.0.0.0[7f7c5009e000+32000]
[17625.392368] Code: 31 ff 48 8d 15 cb 80 01 00 be 10 00 00 00 31 c0 e8 67 3e fe ff 4c 89 e7 e8 9f 51 fe ff e8 0a 59 fe ff 48 89 c5 e8 a2 44 fe ff <48> 8b 7b 20 48 89 c6 e8 e6 3c fe ff 48 89 c7 e8 be 36 fe ff 48 89

And removing one by one, every flag from GentooLTO from these packages: net-libs/libnma dev-python/pygobject dev-libs/gobject-introspection dev-libs/gobject-introspection-common didn't help, the logs stay the same and the segfault on libnma persists.

EDIT: Nevermind, it seems it's a known bug, see: https://bugs.gentoo.org/show_bug.cgi?id=840317