The julianightlies PPA at some point moved the documentation into a separate package, julia-doc, that seems to have a slight problem:
julia> help(help) ERROR: could not open file /usr/share/doc/julia/helpdb.jl in include at ./boot.jl:242 in include_from_node1 at ./loading.jl:128 in evalfile at loading.jl:168 (repeats 2 times) in init_help at help.jl:39 in help at help.jl:89 in help at help.jl:166 in help at help.jl:181 My guess is that the problem is that, as is common in Debian packages, the files in the julia-doc package are gzipped and the help() function doesn't expect that. Indeed, after running sudo gunzip /usr/share/doc/julia/helpdb.jl.gz the help() function seems to work in the REPL again.
