Use eager Pkg server registry instead of git cloning (#31)

* Use eager Pkg server registry instead of git cloning

This patch removes the git cloning of General and instead uses the eager
registry flavor. In addition, the action exits early if no deps/build.jl
file exist.

* Use env: key instead.

action.yml

@@ -17,18 +17,12 @@ inputs:
 runs:
   using: 'composite'
   steps:
-    # Occasionally, there are rather large delays (> a few hours)
-    # between the time a package is registered in General and
-    # propagated to pkg.julialang.org.  We can avoid this by manually
-    # cloning ~/.julia/registries/General/ in Julia 1.5 and later.
-    # See:
-    # * https://github.com/JuliaLang/Pkg.jl/issues/2011
-    # * https://github.com/JuliaRegistries/General/issues/16777
-    # * https://github.com/JuliaPackaging/PkgServer.jl/issues/60
-  - run: julia --color=yes "$GITHUB_ACTION_PATH"/add_general_registry.buildpkg.jl
-    shell: bash
-
-  - run: julia --color=yes --project=${{ inputs.project }} -e 'using Pkg; if VERSION >= v"1.1.0-rc1"; Pkg.build(verbose=true); else Pkg.build(); end'
-    shell: bash
+  - run: |
+      isfile("deps/build.jl") || exit()
+      import Pkg
+      VERSION >= v"1.5-" && Pkg.Registry.add("General")
+      VERSION >= v"1.1.0-rc1" ? Pkg.build(verbose=true) : Pkg.build()
+    shell: julia --color=yes --project=${{ inputs.project }} {0}
     env:
+      JULIA_PKG_SERVER_REGISTRY_PREFERENCE: "${{ env.JULIA_PKG_SERVER_REGISTRY_PREFERENCE == '' && 'eager' || env.JULIA_PKG_SERVER_REGISTRY_PREFERENCE }}"
       JULIA_PKG_PRECOMPILE_AUTO: "${{ inputs.precompile }}"

add_general_registry.buildpkg.jl

@@ -1,73 +0,0 @@
-using Pkg
-
-function tarball_general_registry_location()
-    reg_dir = joinpath(DEPOT_PATH[1], "registries")
-    general_registry_tarball = joinpath(reg_dir, "General.tar.gz")
-    registry_toml_file = joinpath(reg_dir, "General.toml")
-    return general_registry_tarball, registry_toml_file
-end
-
-function cloned_general_registry_location()
-    general_registry_dir = joinpath(DEPOT_PATH[1], "registries", "General")
-    registry_toml_file = joinpath(general_registry_dir, "Registry.toml")
-    return general_registry_dir, registry_toml_file
-end
-
-function general_registry_exists()
-    general_registry_tarball, registry_toml_file = tarball_general_registry_location()
-    if isfile(general_registry_tarball) && isfile(registry_toml_file)
-        return true
-    end
-
-    general_registry_dir, registry_toml_file = cloned_general_registry_location()
-    if isdir(general_registry_dir) && isfile(registry_toml_file)
-        return true
-    end
-
-    return false
-end
-
-function add_general_registry()
-    @info("Attempting to install the General registry")
-
-    general_registry_tarball, registry_toml_file = tarball_general_registry_location()
-    rm(general_registry_tarball; force = true, recursive = true)
-    rm(registry_toml_file; force = true, recursive = true)
-
-    general_registry_dir, registry_toml_file = cloned_general_registry_location()
-    rm(general_registry_dir; force = true, recursive = true)
-
-    # If not already set, We set `JULIA_PKG_SERVER` to enforce
-    # `Pkg.Registry.add` to use Git.  This way, Pkg.jl can send
-    # the request metadata to pkg.julialang.org when installing
-    # packages via `Pkg.test`.
-    pkg_server = get(ENV, "JULIA_PKG_SERVER", "")
-    withenv("JULIA_PKG_SERVER" => pkg_server) do
-        Pkg.Registry.add("General")
-    end
-
-    general_registry_exists() || throw(ErrorException("The Registry was not intalled properly"))
-    return nothing
-end
-
-function main(; n = 10, max_delay = 120)
-    VERSION >= v"1.5-" || return
-
-    if general_registry_exists()
-        @info("The General registry already exists locally")
-        return
-    end
-
-    delays = ExponentialBackOff(; n = n, max_delay = max_delay)
-    try
-        retry(add_general_registry; delays = delays)()
-        @info("Successfully added the General registry")
-    catch ex
-        msg = "I was unable to add the General registry. However, the build will continue."
-        @error(msg, exception=(ex,catch_backtrace()))
-    end
-
-    return
-end
-
-main()