无法找到牛fly包？

Question

在Windows 10计算机上使用Julia 0.5.0和Emacs 25.1，我试图使用Gadfly软件包。不幸的是，出现以下输出：

C:\Users\CaitlinG>julia -e "using Gadfly"
ERROR: ArgumentError: Module Gadfly not found in current path.
Run `Pkg.add("Gadfly")` to install the Gadfly package.
 in require(::Symbol) at .\loading.jl:365
 in eval(::Module, ::Any) at .\boot.jl:234
 in process_options(::Base.JLOptions) at .\client.jl:239
 in _start() at .\client.jl:318

C:\Users\CaitlinG>julia -e "Pkg.add(\"Gadfly\")"
INFO: Nothing to be done
INFO: METADATA is out-of-date — you may not have the latest version of Gadfly
INFO: Use `Pkg.update()` to get the latest versions of your packages

C:\Users\CaitlinG>julia -e "Pkg.update()"
INFO: Updating METADATA...
INFO: Updating cache of DataFrames...
INFO: Updating cache of DataFrames...
INFO: Computing changes...
INFO: No packages to install, update or remove

有谁知道为什么会这样？

感谢。