大家好，今天我在pkg.up之后发现无法使用Plots函数了，具体报错如下：（Julia-1.0.5)
julia> using Plots
[ Info: Precompiling Plots [91a5bcdd-55d7-5caf-9e0b-520d859cae80]
ERROR: LoadError: UndefVarError: ffmpeg not defined
Stacktrace:
[1] top-level scope at none:0
[2] include at ./boot.jl:317 [inlined]
[3] include_relative(::Module, ::String) at ./loading.jl:1044
[4] include(::Module, ::String) at ./sysimg.jl:29
[5] top-level scope at none:2
[6] eval at ./boot.jl:319 [inlined]
[7] eval(::Expr) at ./client.jl:393
[8] top-level scope at ./none:3
in expression starting at /home/weikang_li/.julia/packages/FFMPEG/bkWgb/src/FFMPEG.jl:55
ERROR: LoadError: Failed to precompile FFMPEG [c87230d0-a227-11e9-1b43-d7ebe4e7570a] to /home/weikang_li/.julia/compiled/v1.0/FFMPEG/TGvga.ji.
Stacktrace:
[1] error(::String) at ./error.jl:33
[2] compilecache(::Base.PkgId, ::String) at ./loading.jl:1203
[3] _require(::Base.PkgId) at ./loading.jl:960
[4] require(::Base.PkgId) at ./loading.jl:858
[5] require(::Module, ::Symbol) at ./loading.jl:853
[6] include at ./boot.jl:317 [inlined]
[7] include_relative(::Module, ::String) at ./loading.jl:1044
[8] include(::Module, ::String) at ./sysimg.jl:29
[9] top-level scope at none:2
[10] eval at ./boot.jl:319 [inlined]
[11] eval(::Expr) at ./client.jl:393
[12] top-level scope at ./none:3
in expression starting at /home/weikang_li/.julia/packages/Plots/h3o4c/src/Plots.jl:11
ERROR: Failed to precompile Plots [91a5bcdd-55d7-5caf-9e0b-520d859cae80] to /home/weikang_li/.julia/compiled/v1.0/Plots/ld3vC.ji.
Stacktrace:
[1] error(::String) at ./error.jl:33
[2] compilecache(::Base.PkgId, ::String) at ./loading.jl:1203
[3] _require(::Base.PkgId) at ./loading.jl:960
[4] require(::Base.PkgId) at ./loading.jl:858
[5] require(::Module, ::Symbol) at ./loading.jl:853
提示是ffmpeg出了问题，同时预编译QuAlgorithmZoo时提示了SymEngine没有配置好。
请问大家有遇到类似的情况吗，如果当前没有修复方式的话是不是要等到修复之后再pkg.update才可以呢？谢谢!
谢谢！build之后Plots的问题解决了，现在就剩下SymEngine的bug修复了。
感谢
Error: Error building `SymEngine`:
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libgmp.so
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libmpfr.so
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libmpc.so
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libsymengine.so
| [ Info: Found a valid dl path libgmp.so while looking for libgmp
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libgmp.so matches our search criteria of libgmp
| [ Info: Found a valid dl path libgmp.so while looking for libmpfr
| [ Info: Found a valid dl path libgmp.so.10 while looking for libmpfr
| [ Info: Found a valid dl path libgmp.so.10.3.2 while looking for libmpfr
| [ Info: Found a valid dl path libgmpxx.so while looking for libmpfr
| [ Info: Found a valid dl path libgmpxx.so.4 while looking for libmpfr
| [ Info: Found a valid dl path libgmpxx.so.4.5.2 while looking for libmpfr
| [ Info: Found a valid dl path libmpc.so while looking for libmpfr
| [ Info: Found a valid dl path libmpc.so.3 while looking for libmpfr
| [ Info: Found a valid dl path libmpc.so.3.1.0 while looking for libmpfr
| [ Info: Found a valid dl path libmpfr.so while looking for libmpfr
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libmpfr.so matches our search criteria of libmpfr
| [ Info: Found a valid dl path libgmp.so while looking for libmpc
| [ Info: Found a valid dl path libgmp.so.10 while looking for libmpc
| [ Info: Found a valid dl path libgmp.so.10.3.2 while looking for libmpc
| [ Info: Found a valid dl path libgmpxx.so while looking for libmpc
| [ Info: Found a valid dl path libgmpxx.so.4 while looking for libmpc
| [ Info: Found a valid dl path libgmpxx.so.4.5.2 while looking for libmpc
| [ Info: Found a valid dl path libmpc.so while looking for libmpc
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libmpc.so matches our search criteria of libmpc
| [ Info: Found a valid dl path libgmp.so while looking for libsymengine
| [ Info: Found a valid dl path libgmp.so.10 while looking for libsymengine
| [ Info: Found a valid dl path libgmp.so.10.3.2 while looking for libsymengine
| [ Info: Found a valid dl path libgmpxx.so while looking for libsymengine
| [ Info: Found a valid dl path libgmpxx.so.4 while looking for libsymengine
| [ Info: Found a valid dl path libgmpxx.so.4.5.2 while looking for libsymengine
| [ Info: Found a valid dl path libmpc.so while looking for libsymengine
| [ Info: Found a valid dl path libmpc.so.3 while looking for libsymengine
| [ Info: Found a valid dl path libmpc.so.3.1.0 while looking for libsymengine
| [ Info: Found a valid dl path libmpfr.so while looking for libsymengine
| [ Info: Found a valid dl path libmpfr.so.6 while looking for libsymengine
| [ Info: Found a valid dl path libmpfr.so.6.0.2 while looking for libsymengine
| [ Info: Found a valid dl path libsymengine.so while looking for libsymengine
| [ Info: /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/libsymengine-0.4/lib/libsymengine.so matches our search criteria of libsymengine
| ERROR: LoadError: SystemError: opening file /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/deps.jl: Permission denied
| Stacktrace:
| [1] #systemerror#39(::Nothing, ::Function, ::String, ::Bool) at ./error.jl:106
| [2] systemerror at ./error.jl:106 [inlined]
| [3] #open#295(::Nothing, ::Nothing, ::Nothing, ::Bool, ::Nothing, ::Function, ::String) at ./iostream.jl:283
| [4] #open at ./none:0 [inlined]
| [5] open(::String, ::String) at ./iostream.jl:339
| [6] #open#296(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::getfield(BinaryProvider, Symbol("##154#158")){Bool,String,Array{LibraryProduct,1},getfield(BinaryProvider, Symbol("##153#157")),SubString{String}}, ::String, ::Vararg{String,N} where N) at ./iostream.jl:367
| [7] open at ./iostream.jl:367 [inlined]
| [8] #write_deps_file#152(::Bool, ::Function, ::String, ::Array{LibraryProduct,1}) at /home/weikang_li/.julia/packages/BinaryProvider/TcAwt/src/Products.jl:419
| [9] write_deps_file(::String, ::Array{LibraryProduct,1}) at /home/weikang_li/.julia/packages/BinaryProvider/TcAwt/src/Products.jl:395
| [10] top-level scope at none:0
| [11] include at ./boot.jl:317 [inlined]
| [12] include_relative(::Module, ::String) at ./loading.jl:1044
| [13] include(::Module, ::String) at ./sysimg.jl:29
| [14] include(::String) at ./client.jl:392
| [15] top-level scope at none:0
| in expression starting at /home/weikang_li/.julia/packages/SymEngine/zSUGO/deps/build.jl:60
permission denied 的问题，检查文件是否存在，以及文件权限是否有问题，实在不行就sudo julia
收到，我把.julia这个folder全部删了重装，现在恢复正常了，应该是之前的安装操作不好出了问题。谢谢你！
和楼主一样的问题吗？
略有差异建议直接发帖，带上报错信息、julia 的版本信息，以及已安装的包。
不过一般来说，国内都是网络问题，不能用就是网不行，依赖没下全。
这个问题我前几天又碰到了，是因为在build.jl里要调用deps.jl并写入，要把deps.jl的只读模式取消掉就行了