Plots是Julia语言中的绘图第三方包之一，下面是我使用时遇到的问题，欢迎大家讨论，希望大神们帮助解决问题，这里先谢谢啦：人人为我，我为人人。
下面报错其实就是两个问题：
1.using Plots >>> ERROR: LoadError: FFMPEG not installed properly, run ] build FFMPEG, restart Julia and try again
2.Pkg.build(“FFMPEG”) >>> ERROR: LoadError: LoadError: syntax: “<” is not a unary operator
julia> using Plots
[ Info: Precompiling Plots [91a5bcdd-55d7-5caf-9e0b-520d859cae80]
Deps path: C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\src\..\deps\deps.jl
ERROR: LoadError: FFMPEG not installed properly, run `] build FFMPEG`, restart Julia and try again
Stacktrace:
[1] error(::String) at .\error.jl:33
[2] top-level scope at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\src\FFMPEG.jl:18
[3] include at .\boot.jl:328 [inlined]
[4] include_relative(::Module, ::String) at .\loading.jl:1094
[5] include(::Module, ::String) at .\Base.jl:31
[6] top-level scope at none:2
[7] eval at .\boot.jl:330 [inlined]
[8] eval(::Expr) at .\client.jl:432
[9] top-level scope at .\none:3
in expression starting at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\src\FFMPEG.jl:16
ERROR: LoadError: Failed to precompile FFMPEG [c87230d0-a227-11e9-1b43-d7ebe4e7570a] to C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\compiled\v1.2\FFMPEG\TGvga.ji.
Stacktrace:
[1] error(::String) at .\error.jl:33
[2] compilecache(::Base.PkgId, ::String) at .\loading.jl:1253
[3] _require(::Base.PkgId) at .\loading.jl:1013
[4] require(::Base.PkgId) at .\loading.jl:911
[5] require(::Module, ::Symbol) at .\loading.jl:906
[6] include at .\boot.jl:328 [inlined]
[7] include_relative(::Module, ::String) at .\loading.jl:1094
[8] include(::Module, ::String) at .\Base.jl:31
[9] top-level scope at none:2
[10] eval at .\boot.jl:330 [inlined]
[11] eval(::Expr) at .\client.jl:432
[12] top-level scope at .\none:3
in expression starting at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\Plots\WwFyB\src\Plots.jl:11
ERROR: Failed to precompile Plots [91a5bcdd-55d7-5caf-9e0b-520d859cae80] to C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\compiled\v1.2\Plots\ld3vC.ji.
Stacktrace:
[1] compilecache(::Base.PkgId, ::String) at .\loading.jl:1253
[2] _require(::Base.PkgId) at .\loading.jl:1013
[3] require(::Base.PkgId) at .\loading.jl:911
[4] require(::Module, ::Symbol) at .\loading.jl:906
julia> Pkg.build("FFMPEG") Building FFMPEG → `C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build.log`
┌ Error: Error building `FFMPEG`:
│ ERROR: LoadError: LoadError: syntax: "<" is not a unary operator
│ Stacktrace:
│ [1] top-level scope at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build_Bzip2.v1.0.6.jl:1
│ [2] include at .\boot.jl:328 [inlined]
│ [3] include_relative(::Module, ::String) at .\loading.jl:1094
│ [4] include at .\Base.jl:31 [inlined]
│ [5] include(::String) at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build.jl:51
│ [6] top-level scope at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build.jl:52
│ [7] include at .\boot.jl:328 [inlined]
│ [8] include_relative(::Module, ::String) at .\loading.jl:1094
│ [9] include(::Module, ::String) at .\Base.jl:31
│ [10] include(::String) at .\client.jl:431
│ [11] top-level scope at none:5
│ in expression starting at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build_Bzip2.v1.0.6.jl:1
│ in expression starting at C:\Users\lenovo\.juliapro\JuliaPro_v1.2.0-1\packages\FFMPEG\8bbhD\deps\build.jl:44
└ @ Pkg.Operations C:\Users\julia\AppData\Local\Julia-1.2.0\share\julia\stdlib\v1.2\Pkg\src\Operations.jl:1138