# Error with package versions when installing Merlin.jl in Julia 1.0

**URL:** <https://discourse.julialang.org/t/error-with-package-versions-when-installing-merlin-jl-in-julia-1-0/15540>\
**Category:** General Usage\
**Created:** [September 27, 2018, 4:11am UTC](https://discourse.julialang.org/t/error-with-package-versions-when-installing-merlin-jl-in-julia-1-0/15540 "2018-09-27T04:11:03Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![1113](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/1113/32/205603_2.png) [@1113](https://discourse.julialang.org/u/1113)\
**Post date:** [September 27, 2018, 4:11am UTC](https://discourse.julialang.org/t/error-with-package-versions-when-installing-merlin-jl-in-julia-1-0/15540/1 "2018-09-27T04:11:03Z")

</div>

Error occur when I was trying to install Merlin.jl package with Pkg in Julia 1.0.  
It is really confusing as it is not explicitly shown which requirement is unsatisfied.  
Error message:

> julia\> Pkg.add(“Merlin”)  
> Updating registry at `C:\Users\Administrator\.julia\registries\General`  
> Updating git-repo `https://github.com/JuliaRegistries/General.git`  
> Resolving package versions…  
> ERROR: Unsatisfiable requirements detected for package Merlin [80f3d04f]:  
> Merlin [80f3d04f] log:  
> ├─possible versions are: 0.0.1-0.0.3 or uninstalled  
> ├─restricted to versions \* by an explicit requirement, leaving only versions 0.0.1-0.0.3  
> └─restricted by julia compatibility requirements to versions: uninstalled — no versions left  
> Stacktrace:  
> [1] #propagate\_constraints!#61(::Bool, ::Function, ::Pkg.GraphType.Graph, ::Set{Int64}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\GraphType.jl:1005  
> [2] propagate\_constraints! at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\GraphType.jl:946 [inlined]  
> [3] #simplify\_graph!#121(::Bool, ::Function, ::Pkg.GraphType.Graph, ::Set{Int64}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\GraphType.jl:1460  
> [4] simplify\_graph! at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\GraphType.jl:1460 [inlined]  
> [5] macro expansion at .\logging.jl:311 [inlined]  
> [6] resolve\_versions!(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\Operations.jl:339  
> [7] #add\_or\_develop#58(::Array{Base.UUID,1}, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\Operations.jl:1163  
> [8] #add\_or\_develop at .\none:0 [inlined]  
> [9] #add\_or\_develop#13(::Symbol, ::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:64  
> [10] #add\_or\_develop at .\none:0 [inlined]  
> [11] #add\_or\_develop#12 at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:29 [inlined]  
> [12] #add\_or\_develop at .\none:0 [inlined]  
> [13] #add\_or\_develop#11(::Base.Iterators.Pairs{Symbol,Symbol,Tuple{Symbol},NamedTuple{(:mode,),Tuple{Symbol}}}, ::Function, ::Array{String,1}) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:28  
> [14] #add\_or\_develop at .\none:0 [inlined]  
> [15] #add\_or\_develop#10 at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:27 [inlined]  
> [16] #add\_or\_develop at .\none:0 [inlined]  
> [17] #add#18 at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:69 [inlined]  
> [18] add(::String) at C:\cygwin\home\Administrator\buildbot\worker\package\_win64\build\usr\share\julia\stdlib\v1.0\Pkg\src\API.jl:69  
> [19] top-level scope at none:0

Such confusing error occurs in Julia 1.0 more than once, how can I fix it?