tuned signature (again, amending f32ac01aef5e), e.g. relevant for Isabelle/DOF;
#!/usr/bin/env bash
set -e
$ISABELLE_LUALATEX root
if [ -f manual.bib -o -f root.bib ]
then
$ISABELLE_BIBTEX root
$ISABELLE_LUALATEX root
fi
$ISABELLE_LUALATEX root
if [ -f root.idx ]
then
"$ISABELLE_HOME/src/Doc/sedindex" root
$ISABELLE_LUALATEX root
fi