asciidoc: reading: /etc/asciidoc/asciidoc.conf
asciidoc: reading: /etc/asciidoc/xhtml11.conf
asciidoc: reading: /etc/asciidoc/xhtml11-quirks.conf
asciidoc: reading: /etc/asciidoc/filters/graphviz/graphviz-filter.conf
asciidoc: reading: /etc/asciidoc/filters/music/music-filter.conf
asciidoc: reading: /etc/asciidoc/filters/source/source-highlight-filter.conf
asciidoc: reading: /etc/asciidoc/filters/code/code-filter.conf
asciidoc: reading: /etc/asciidoc/lang-en.conf
asciidoc: reading: /home/john/tutorials/tuning/halscope.txt
asciidoc: writing: /home/john/tutorials/tuning/halscope.html
asciidoc: FAILED: halscope.txt: line 20: undefined filter attribute in command: graphviz2png.py {verbose?-v} -o "{outdir={indir}}/{imagesdir=}{imagesdir?/}{target}" -L {layout=dot} -