According to bug 238511 , Vacuum Defs on the command line isn't safe. I've just tested this, and it's true, so I would avoid using --vacuum-defs. This bug doesn't produce any error message (the error message you're seeing is probably bug 236816 , which is unrelated). Thanks for the info. This answe...

Hi, this is probably a stupid newbie question, but when using the "for i in *.svg; do inkscape --vacuum-defs $i; done" command, I get the following error for a lot of files: ** (inkscape:XXXX): CRITICAL **: void Inkscape::GC::Anchored::release() const: assertion `_anchor' failed I develop ...