reopen 963983 thanks The other pyside2 packages (code, gui etc) were still at 5.15.0-1~exp1.
If I just update qtsvg to 5.15.0-2 the segfault still happens. Update the rest of pyside2 triggers a huge cascading of upgrades to Qt 5.14 which had not been done when I had installed the exp packages, and when I updated qtsvg initially. Among them: Unpacking libqt5svg5:amd64 (5.14.2-2) over (5.12.5-2) ... With all this upgraded, I confirm there is no segfault any more. Thus, the problem is likely caused by an undeclared versioned dependency on an underlying lib, and libqt5svg5 looks like a good candidate. Not dealing with it is likely to lead to other insufficient partial updates.