I have written a small tool to do textual replacements in the declarations,
instantiation, and system section of a Uppaal model in XML format, so the same
model can easily be verified against different parameters.

This tool produces XML that is slightly different from the XML generated by the
GUI, but functionally equivalent.

However, verifyta fails to read the models output by my tool, and I traced this
to the <nail> element.  The GUI produces XML with nails written as <nail x="1"
y="1"/>.  My tool outputs this as <nail x="1" y="1"></nail>, which, as I
understand it, is equivalent XML syntax to the GUI version.

But verifyta fails to read this, and seems stuck in an infinite loop.

Interestingly, verifyta does not have this problem with <source> and <target> tags.

Attached is a simple model in two versions: the Uppaal GUI produced one and the
one produced by my tool.

In the meantime I changed my tool such that it outputs differently for <nail> tags.