SUMMARY
umbrello5 git-2.37.90-09bb3b4d7 runs fine on my platform (amd64/devuan stable).
Only this test fails:
gdb ./testumlroledialog

The test crashes with the following back trace:
Reading symbols from ./testumlroledialog...
(gdb) r
Starting program: /home/fabien/umbrello/build-amd64/unittests/testumlroledialog 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff07ff6c0 (LWP 3447)]
[New Thread 0x7fffeef876c0 (LWP 3448)]
[New Thread 0x7fffee6ed6c0 (LWP 3450)]
[New Thread 0x7fffedeec6c0 (LWP 3451)]
kf.i18n: KLocalizedString: Using an empty domain, fix the code. msgid: "Your emails" msgid_plural: "" msgctxt: "EMAIL OF TRANSLATORS"
kf.i18n: KLocalizedString: Using an empty domain, fix the code. msgid: "Your names" msgid_plural: "" msgctxt: "NAME OF TRANSLATORS"

Thread 1 "testumlroledial" received signal SIGSEGV, Segmentation fault.
0x0000555555678140 in UMLApp::document (this=0x0) at /home/fabien/umbrello/umbrello/uml.cpp:1053
1053	    return m_doc;
(gdb) bt
#0  0x0000555555678140 in UMLApp::document() const (this=0x0) at /home/fabien/umbrello/umbrello/uml.cpp:1053
#1  0x0000555555636292 in UMLObject::UMLObject(QString const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) (this=0x7fffffffe0b0, name=..., id="-1") at /home/fabien/umbrello/umbrello/umlmodel/umlobject.cpp:86
#2  0x0000555555630df8 in UMLStereotype::UMLStereotype() (this=0x7fffffffe0b0)
    at /home/fabien/umbrello/umbrello/umlmodel/stereotype.cpp:42
#3  0x0000555555622944 in main(int, char**) (argc=1, argv=0x7fffffffe5d8) at /home/fabien/umbrello/unittests/testumlroledialog.cpp:23
(gdb)


SOFTWARE/OS VERSIONS
Linux devuan: daedalus 
KDE frameworks: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
xcb window system