julia> Pkg.checkout("Logging")
INFO: No packages to install, update or remove
julia> Pkg.status("Logging")
- Logging 0.2.0+ master
julia> using Logging
WARNING: Method definition info(Any...) in module Base at util.jl:320 overwritten in module Logging at /home/josh/.julia/v0.5/Logging/src/Logging.jl:104.
WARNING: Method definition warn(Any...) in module Base at util.jl:350 overwritten in module Logging at /home/josh/.julia/v0.5/Logging/src/Logging.jl:104.
julia> log
WARNING: both Logging and Base export "log"; uses of it in module Main must be qualified
ERROR: UndefVarError: log not defined