[SOLVED] Is there any way to build package dependency tree in julia-lang?

Is there any way to build package dependency tree in julia-lang?

Using npm list will show a tree of installed packages, versions and relations:

Although Julia package management is differ (e.g normally no duplicate copy of a package exists), But is there any way to:

Know why one package have been installed?
or build a package dependency tree.

Solution

I don't think there's a simple function, but it shouldn't be too hard to do with these two functions:

julia> Pkg.dependents("Cairo")
10-element Array{AbstractString,1}:
 "Tk"
 "Gtk"
 "Mamba"
 "Drawing"
 "GtkUtilities"
 "ProfileView"
 "Brim"
 "Winston"
 "EcologicalNetwork"
 "VennEuler"

julia> Pkg.installed()
Dict{ASCIIString,VersionNumber} with 119 entries:
  "Libz"             => v"0.0.2"
  "Gtk"              => v"0.9.3"
  "Interact"         => v"0.3.0"
  "ForwardDiff"      => v"0.1.4"
  "Benchmark"        => v"0.1.0"
  "AxisAlgorithms"   => v"0.1.4"
  "Cairo"            => v"0.2.31+"
  "HttpParser"       => v"0.1.1"
  "DataFrames"       => v"0.6.10"
  "Requests"         => v"0.3.4"
  "QuartzImageIO"    => v"0.1.0+"
  "Markdown"         => v"0.3.0"
  "Requires"         => v"0.2.2"
  "ArgParse"         => v"0.3.0"
  ⋮                  => ⋮