Add RCall.debuginfo() helper to clarify RCall environment

Author: Frankie Robertson

src/RCall.jl

@@ -56,6 +56,7 @@ if Rhome == ""
     __precompile__(false)
 end
 
+include("versioninfo.jl")
 include("types.jl")
 include("Const.jl")
 include("methods.jl")

src/versioninfo.jl

@@ -0,0 +1,33 @@
+"""
+Print some useful information about the current RCall.jl setup.
+If `all` is false, only RCall.jl information is printed, otherwise
+information about your Julia and R setup is printed as well.
+"""
+function versioninfo(; all=true)
+    if all
+        println("RCall.jl information:")
+    end
+    version = pkgversion(RCall)
+    prefix = all ? "\t" : ""
+    println("$(prefix)RCall.jl version $version")
+    println("$(prefix)R location configured with Preferences.jl: $Rhome_set_as_preference")
+    println("$(prefix)RCall.jl managed R using Conda.jl: $conda_provided_r")
+    println("$(prefix)Rhome: $Rhome")
+    println("$(prefix)libR: $libR")
+    if all
+        println()
+        println("Julia information:")
+        buffer = IOBuffer()
+        Main.versioninfo(buffer)
+        seek(buffer, 0)
+        for line in eachline(buffer)
+            println("\t" * line)
+        end
+        println()
+        println("R information:")
+        lines = reval("capture.output(sessionInfo())")
+        for line in lines
+            println("\t" * rcopy(line))
+        end
+    end
+end