catch crash in Mix.Project.deps_paths

Author: lukaszsamson

apps/language_server/lib/language_server/build.ex

@@ -141,7 +141,20 @@ defmodule ElixirLS.LanguageServer.Build do
       if module = Mix.Project.get() do
         build_path = Mix.Project.config()[:build_path]
 
-        for {app, path} <- Mix.Project.deps_paths() do
+        deps_paths =
+          try do
+            # this call can raise (RuntimeError) cannot retrieve dependencies information because dependencies
+            # were not loaded. Please invoke one of "deps.loadpaths", "loadpaths", or "compile" Mix task
+            Mix.Project.deps_paths()
+          catch
+            kind, payload ->
+              {payload, stacktrace} = Exception.blame(kind, payload, __STACKTRACE__)
+              message = Exception.format(kind, payload, stacktrace)
+              Logger.warning("Unable to prune mix project: #{message}")
+              []
+          end
+
+        for {app, path} <- deps_paths do
           child_module =
             try do
               Mix.Project.in_project(app, path, [build_path: build_path], fn mix_project ->