From 8510ecce6bae89afd811b888b72f2122b28fcccf Mon Sep 17 00:00:00 2001
From: Fons van der Plas <fonsvdplas@gmail.com>
Date: Wed, 11 Dec 2024 10:07:25 +0100
Subject: [PATCH] Warn when using future Julia versions

---
 src/Pluto.jl               | 34 ++++++++++++++++++++++++----------
 src/webserver/WebServer.jl |  4 +---
 2 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/src/Pluto.jl b/src/Pluto.jl
index 9763436f2..c44764ec7 100644
--- a/src/Pluto.jl
+++ b/src/Pluto.jl
@@ -98,6 +98,28 @@ include("./precompile.jl")
 
 const pluto_boot_environment_path = Ref{String}()
 
+function warn_julia_compat()
+    if VERSION > v"1.11.9999"
+        @warn("\nPluto ($(PLUTO_VERSION)) is running on a new version of Julia ($(VERSION)).\n\n$(
+            # if using a regular Julia version, then that means that the new Julia version has been released and we released a new Pluto version that supports it, but the user is still using an old Pluto version.
+            VERSION.prerelease === () && VERSION.build === () ?
+            "You need to update Pluto to use this Julia version, see https://plutojl.org/en/docs/update/ to learn more." :
+            # if using a build/prerelease, then the user is using a future Julia version that we don't support yet.
+            "This (preview) version of Julia might not be fully supported by Pluto yet. Please check back later or use an older version of Julia."
+        )")
+    end
+    
+    bad_depots = filter(d -> !isabspath(expanduser(d)), DEPOT_PATH)
+    if !isempty(bad_depots)
+        @error """Pluto: The provided depot path is not an absolute path. Pluto will not be able to run correctly.
+        
+        Did you recently change the DEPOT path setting? Change your setting to use an absolute path.
+        
+        Do you not know what this means? Please get in touch! https://github.com/fonsp/Pluto.jl/issues
+        """ bad_depots DEPOT_PATH
+    end
+end
+
 function __init__()
     pluto_boot_environment_name = "pluto-boot-environment-$(VERSION)-$(PLUTO_VERSION)"
     pluto_boot_environment_path[] = Scratch.@get_scratch!(pluto_boot_environment_name)
@@ -125,17 +147,9 @@ function __init__()
             # create empty file to indicate that we've shown the banner
             write(fn, "");
         end
-
-        bad_depots = filter(d -> !isabspath(expanduser(d)), DEPOT_PATH)
-        if !isempty(bad_depots)
-            @error """Pluto: The provided depot path is not an absolute path. Pluto will not be able to run correctly.
-            
-            Did you recently change the DEPOT path setting? Change your setting to use an absolute path.
-            
-            Do you not know what this means? Please get in touch! https://github.com/fonsp/Pluto.jl/issues
-            """ bad_depots DEPOT_PATH
-        end
     end
+    
+    warn_julia_compat()
 end
 
 end
diff --git a/src/webserver/WebServer.jl b/src/webserver/WebServer.jl
index 6c96f621c..54c12c0d5 100644
--- a/src/webserver/WebServer.jl
+++ b/src/webserver/WebServer.jl
@@ -145,9 +145,7 @@ function run!(session::ServerSession)
         @info "Loading..."
     end
 
-    if VERSION < v"1.10.0"
-        @warn("\nPluto is running on an old version of Julia ($(VERSION)) that is no longer supported. Visit https://julialang.org/downloads/ for more information about upgrading Julia.")
-    end
+    warn_julia_compat()
 
     pluto_router = http_router_for(session)
     store_session_middleware = create_session_context_middleware(session)