fix list in message

base/loading.jl

@@ -1394,8 +1394,8 @@ function run_extension_callbacks(pkgid::PkgId)
     for extid in extids
         if in(extid.id, precompilation_stack) && !isprecompiled(extid.id)
             @debug """
-            Dependency cycle detected in extension precompilation: $(join(precompilation_stack, " > ")) > $(extid.id.name)
-            $(extid.id) will not be loaded here.
+            Dependency cycle detected in extension precompilation: $(precompilation_stack_list()) > $(extid.id.name)
+            $(extid.id.name) will not be loaded here.
             """
             continue
         end
@@ -2525,14 +2525,14 @@ function create_expr_cache(pkg::PkgId, input::String, output::String, output_o::
 end
 
 const precompilation_stack = Vector{PkgId}()
+precompilation_stack_list() = join(map(p->p.name, precompilation_stack), " > ")
 # Helpful for debugging when precompilation is unexpectedly nested.
 # Enable with `JULIA_DEBUG=nested_precomp`. Note that it expected to be nested in classical code-load precompilation
 # TODO: Add detection if extension precompilation is nested and error / return early?
 function track_nested_precomp(pkgs::Vector{PkgId})
     append!(precompilation_stack, pkgs)
     if length(precompilation_stack) > 1
-        list() = join(map(p->p.name, precompilation_stack), " > ")
-        @debug "Nested precompilation: $(list())" _group=:nested_precomp
+        @debug "Nested precompilation: $(precompilation_stack_list())" _group=:nested_precomp
     end
 end