raptor/notes/xml_escaping.txt

The output from tools run by Raptor will typically not be XML, so Raptor wraps
all tool output in CDATA sections. For example:

<![CDATA[
+ python write_my_code.py
writing MyClass.hxx
writing MyClass.cpp
]]>

The text between "[CDATA[" and "]]" is arbitrary, however there are some
characters which are not permitted and will be rejected as bad XML by
many XML parsers. Therefore Raptor will also translate these invalid
characters into strings which are valid. For example, control characters
in the ASCII range 0-31 are translated into "&#x00;", "&#x01;", "&#x02" etc.
(except for CTRL-I, CTRL-J and CTRL-M which are allowed).

In general, tools should not be writing non-printable characters to stdout
and stderr anyway. But if they do, then at least you will see something
sensible in the Raptor logs. For example,

<![CDATA[
+ python hack_my_code.py
error: don't hack it you &#xff;
]]>