The secret to happiness in life is never use Qt for anything.
Judging from your error message alone
| In file included from /usr/include/c++/7/list:60:0,
| from ../../../../git/src/3rdparty/chromium/v8/src/torque/cfg.h:8,
| from ./../../../../git/src/3rdparty/chromium/v8/src/torque/cfg.cc:5,
| from v8_snapshot/gen/v8/torque_base_jumbo_1.cc:5:
| /usr/include/c++/7/bits/stl_algobase.h:59:10: fatal error: bits/c++config.h: No such file or directory
| #include <bits/c++config.h>
| ^~~~~~~~~~~~~~~~~~
| compilation terminated.
The Google chromium libraries have 32-bit components
OR
the default recipe assumes a 32-bit target and you need to tweak the recipe to force 64-bit build.
I realize the links I provided aren’t for embedded building but they identify what the problem is.
Sorry, I didn’t understand what went wrong, following the steps here, did you have the same error as before while executing bitbake tdx-reference-multimedia-image?