Strange influence of the package load order on the timing on 0.7rc2

General Usage
1

Strange behaviour:

  | | |_| | | | (_| |  |  Version 0.7.0-rc2.0 (2018-08-02 19:14 UTC)
 _/ |\__'_|_|_|\__'_|  |  
|__/                   |  x86_64-linux-gnu

julia> @time using CSV
  0.827353 seconds (2.88 M allocations: 187.064 MiB, 2.27% gc time)
julia> @time using PyPlot
  5.002150 seconds (17.81 M allocations: 882.956 MiB, 5.82% gc time)

But (after restarting Julia):

julia> @time using PyPlot
  2.899065 seconds (8.82 M allocations: 449.410 MiB, 3.48% gc time)

julia> @time using CSV
  2.080075 seconds (6.44 M allocations: 354.970 MiB, 7.65% gc time)

In other words: The load time of the second package is drastically increased.

Any idea?