Same here:
julia
_
_ _ _(_)_ | Documentation: https://docs.julialang.org
(_) | (_) (_) |
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 1.1.1 (2019-05-16)
_/ |\__'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |
julia> import Pkg; Pkg.add("JSON")
Cloning default registries into `~/.julia`
Cloning registry from "https://github.com/JuliaRegistries/General.git"
ERROR: failed to clone from https://github.com/JuliaRegistries/General.git, error: GitError(Code:ECERTIFICATE, Class:SSL, the SSL certificate is invalid: 0x08 - The certificate is not correctly signed by the trusted CA)
Stacktrace:
[1] pkgerror(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:120
[2] #clone#3(::String, ::Base.Iterators.Pairs{Symbol,LibGit2.CachedCredentials,Tuple{Symbol},NamedTuple{(:credentials,),Tuple{LibGit2.CachedCredentials}}}, ::Function, ::String, ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/GitTools.jl:111
[3] (::getfield(Pkg.GitTools, Symbol("#kw##clone")))(::NamedTuple{(:header, :credentials),Tuple{String,LibGit2.CachedCredentials}}, ::typeof(Pkg.GitTools.clone), ::String, ::String) at ./none:0
[4] (::getfield(Pkg.Types, Symbol("##87#89")))(::LibGit2.CachedCredentials) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1103
[5] shred!(::getfield(Pkg.Types, Symbol("##87#89")), ::LibGit2.CachedCredentials) at ./secretbuffer.jl:184
[6] clone_or_cp_registries(::Pkg.Types.Context, ::Array{Pkg.Types.RegistrySpec,1}, ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1102
[7] clone_or_cp_registries at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1087 [inlined]
[8] clone_default_registries() at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1037
[9] find_registered!(::Pkg.Types.EnvCache, ::Array{String,1}, ::Array{Base.UUID,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:1312
[10] registry_resolve!(::Pkg.Types.EnvCache, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Types.jl:949
[11] #add_or_develop#17(::Symbol, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:52
[12] #add_or_develop at ./none:0 [inlined]
[13] #add_or_develop#16 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:36 [inlined]
[14] #add_or_develop at ./none:0 [inlined]
[15] #add_or_develop#13 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:34 [inlined]
[16] #add_or_develop at ./none:0 [inlined]
[17] #add_or_develop#12(::Base.Iterators.Pairs{Symbol,Symbol,Tuple{Symbol},NamedTuple{(:mode,),Tuple{Symbol}}}, ::Function, ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:33
[18] #add_or_develop at ./none:0 [inlined]
[19] #add#22 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:64 [inlined]
[20] add(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.1/Pkg/src/API.jl:64
[21] top-level scope at none:0
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Codename: bionic
uname -arv
Linux f02c 4.15.0-52-generic #56-Ubuntu SMP Tue Jun 4 22:49:08 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux