Put the General registry clone inside a bounded retry loop (#31)

Co-authored-by: Sascha Mann <git@mail.saschamann.eu>

add_general_registry.jl

@@ -0,0 +1,49 @@
+using Pkg
+
+function 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_dir, registry_toml_file = general_registry_location()
+    if !isdir(general_registry_dir)
+        return false
+    elseif !isfile(registry_toml_file)
+        return false
+    else
+        return true
+    end
+end
+
+function add_general_registry()
+    @info("Attempting to clone the General registry")
+    general_registry_dir, registry_toml_file = general_registry_location()
+    rm(general_registry_dir; force = true, recursive = true)
+    Pkg.Registry.add("General")
+    isfile(registry_toml_file) || throw(ErrorException("the Registry.toml file does not exist"))
+    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 add the General registry")
+    catch ex
+        msg = "I was unable to added the General registry. However, the build will continue."
+        @error(msg, exception=(ex,catch_backtrace()))
+    end
+
+    return
+end
+
+main()