[isabelle-dev] Bad documentation directory

[Lars Hupel]

When I clone a fresh copy of Isabelle, or run "hg clean --all", then
"isabelle build" fails with the following error message:

*** Bad documentation directory:
"/home/lars/work/isabelle/src/Tools/jEdit/dist/doc"

That directory is not present by default and appears to be only created
by "isabelle jedit". A workaround is to always run "isabelle jedit -bf"
before running "isabelle build".