clarified NEWS: document_files are officially required since Isabelle2014, but the absence was tolerated as legacy feature;
#!/usr/bin/env bash
set -e
FORMAT="$1"
VARIANT="$2"
"$ISABELLE_TOOL" logo Isar
./showsymbols "$ISABELLE_HOME/lib/texinputs/isabellesym.sty" > syms.tex
"$ISABELLE_HOME/src/Doc/prepare_document" "$FORMAT"