I run xsltproc with the single file "simple.xml" like this:
xsltproc -o outputfilename.xml /usr/share/sgml/docbook/docbook-xsl-1.64.1/html/html.xsl prueba.xml
After running xsltproc this is the what "outputfilename.xml" contains:
"<"?xml version="1.0"?">"
Test article
This is a test article.
So here everything seems to go fine, but the with the make command, it still doesn't work