ArchGDAL has to be installed before GDAL/must install GDAL itself

[randyzwitch]

I was trying to work through your tutorial, and the way the install commands are written with GDAL first, ArchGDAL won't install.

Not sure if this is something that's easily fixed, just wanted to highlight it.

julia> Pkg.add("ArchGDAL")
 Resolving package versions...
ERROR: Unsatisfiable requirements detected for package GDAL [add2ef01]:
 GDAL [add2ef01] log:
 ├─possible versions are: [0.1.0-0.1.2, 0.2.0, 1.0.0-1.0.1] or uninstalled
 ├─restricted to versions 1.0.1 by an explicit requirement, leaving only versions 1.0.1
 └─restricted by compatibility requirements with ArchGDAL [c9ce4bd3] to versions: 0.2.0 — no versions left
   └─ArchGDAL [c9ce4bd3] log:
     ├─possible versions are: [0.1.0, 0.2.0-0.2.1] or uninstalled
     └─restricted to versions * by an explicit requirement, leaving only versions [0.1.0, 0.2.0-0.2.1]
Stacktrace:
 [1] #propagate_constraints!#61(::Bool, ::typeof(Pkg.GraphType.propagate_constraints!), ::Pkg.GraphType.Graph, ::Set{Int64}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/GraphType.jl:1007
 [2] propagate_constraints! at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/GraphType.jl:948 [inlined]
 [3] #simplify_graph!#121(::Bool, ::typeof(Pkg.GraphType.simplify_graph!), ::Pkg.GraphType.Graph, ::Set{Int64}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/GraphType.jl:1462
 [4] simplify_graph! at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/GraphType.jl:1462 [inlined]
 [5] resolve_versions!(::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/Operations.jl:317
 [6] #add#100(::Bool, ::typeof(Pkg.Operations.add), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}, ::Array{Base.UUID,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/Operations.jl:962
 [7] #add at ./none:0 [inlined]
 [8] #add#25(::Bool, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.add), ::Pkg.Types.Context, ::Array{Pkg.Types.PackageSpec,1}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:99
 [9] add at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:69 [inlined]
 [10] #add#24 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:67 [inlined]
 [11] add at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:67 [inlined]
 [12] #add#21 at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:65 [inlined]
 [13] add at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:65 [inlined]
 [14] #add#20(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.add), ::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:64
 [15] add(::String) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.2/Pkg/src/API.jl:64
 [16] top-level scope at REPL[40]:1

julia> Pkg.rm("GDAL")
  Updating `~/.julia/environments/v1.2/Project.toml`
  [add2ef01] - GDAL v1.0.1
  Updating `~/.julia/environments/v1.2/Manifest.toml`
  [fa961155] - CEnum v0.2.0
  [add2ef01] - GDAL v1.0.1

julia> Pkg.add("ArchGDAL")
 Resolving package versions...
 Installed ArchGDAL ──── v0.2.1
 Installed GDAL ──────── v0.2.0
 Installed DataStreams ─ v0.4.2
  Updating `~/.julia/environments/v1.2/Project.toml`
  [c9ce4bd3] + ArchGDAL v0.2.1
  Updating `~/.julia/environments/v1.2/Manifest.toml`
  [c9ce4bd3] + ArchGDAL v0.2.1
  [9a8bc11e] + DataStreams v0.4.2
  [add2ef01] + GDAL v0.2.0
  [cf35fbd7] + GeoInterface v0.4.1
  [3cdcf5f2] + RecipesBase v0.7.0
  [ea10d353] + WeakRefStrings v0.6.1
  Building GDAL → `~/.julia/packages/GDAL/vec6Y/deps/build.log`

[visr]

Hmmm yeah. The current ArchGDAL release is pinned to GDAL 0.2. If you first install GDAL it will currently install version 1.0.1. Then ArchGDAL will complain it cannot work with that.

We didn't write that blog post, though you could send him a note on this (the Pkg.build step should also not be needed).

In any case we will relieve the version restriction once #76 is merged, though that is now hinged on some binary dependency troubles.

[randyzwitch]

Sorry about that, guess I wasn't reading that carefully 😆