Reproduced on Windows XP, Inkscape 0.48.4 and trunk revision 13395.
Steps:
1. Open the file attached comment #2.
2. Open the XML editor.
3. In the XML editor, select the g with id="g77".
4. Move a selection handle.
No bt, but the following console message:
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** (inkscape.exe:844): WARNING **: The snapmanager has been set up before, but unSetup() hasn't been called afterwards.
It possibly held invalid pointers
Assertion failed: this->is_initialized(), file d:\Dev\devlibs/include/boost/optional/optional.hpp, line 590
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
Program exited with code 03.
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I'll try to get a valid trace on Crunchbang Waldorf later today.
Note that the path with id="path79" is linked to an empty clip-path (url(#SVGID_3_)).
Removing the clip-path attribute with the XML editor solves the issue.
Also reproduced on Crunchbang Waldorf, Inkscape 0.48.3.1 (trace attached).
I can't reproduce it with the trunk because the handles are hidden when selecting the affected object from the XML editor...
U really have to fix crashes GGG!
I already start to feel annoying about this league. It's just impossible to finish a map without crashing 1 or 2 times with a molten strike build!
Not replicated with the instructions from #3 in Inkscape 0.92.4, as well as Inkscape 1.1-dev (c990a67, 2020-04-09), Windows 10. In both cases, selecting the group doesn't show any handles on canvas, probably due to the empty clip-path. Please reopen on http://inkscape.org/report if the problem occurs again.
I've extracted only the relevant blue object.