Add --no-check-pwd to mix compile

Author: josevalim

lib/mix/lib/mix/compilers/elixir.ex

@@ -5,7 +5,7 @@
 defmodule Mix.Compilers.Elixir do
   @moduledoc false
 
-  @manifest_vsn 28
+  @manifest_vsn 29
   @checkpoint_vsn 4
 
   import Record
@@ -49,8 +49,8 @@ defmodule Mix.Compilers.Elixir do
     timestamp = System.os_time(:second)
     all_paths = Mix.Utils.extract_files(srcs, [:ex])
 
-    {all_modules, all_sources, all_local_exports, old_parents, old_cache_key, old_deps_config,
-     old_project_mtime, old_config_mtime, old_protocols_and_impls} =
+    {all_modules, all_sources, all_local_exports, old_parents, old_cache_key, old_cwd,
+     old_deps_config, old_project_mtime, old_config_mtime, old_protocols_and_impls} =
       parse_manifest(manifest, dest)
 
     # In case we aborted in the middle of a verification,
@@ -100,7 +100,8 @@ defmodule Mix.Compilers.Elixir do
 
     {force?, stale, new_deps_config} =
       cond do
-        !!opts[:force] or is_nil(old_deps_config) or old_cache_key != new_cache_key ->
+        !!opts[:force] or is_nil(old_deps_config) or old_cache_key != new_cache_key or
+            (Keyword.get(opts, :check_cwd, true) and old_cwd != File.cwd!()) ->
           {true, stale, deps_config(local_deps)}
 
         deps_changed? or compile_env_apps != [] ->
@@ -313,7 +314,7 @@ defmodule Mix.Compilers.Elixir do
     rescue
       _ -> {[], []}
     else
-      {@manifest_vsn, modules, sources, _, _, _, _, _, _, _} -> {modules, sources}
+      {@manifest_vsn, modules, sources, _, _, _, _, _, _, _, _} -> {modules, sources}
       _ -> {[], []}
     end
   end
@@ -881,7 +882,7 @@ defmodule Mix.Compilers.Elixir do
 
   ## Manifest handling
 
-  @default_manifest {%{}, %{}, %{}, [], nil, nil, 0, 0, {%{}, %{}}}
+  @default_manifest {%{}, %{}, %{}, [], nil, nil, nil, 0, 0, {%{}, %{}}}
 
   # Similar to read_manifest, but for internal consumption and with data migration support.
   defp parse_manifest(manifest, compile_path) do
@@ -891,9 +892,9 @@ defmodule Mix.Compilers.Elixir do
       _ ->
         @default_manifest
     else
-      {@manifest_vsn, modules, sources, local_exports, parent, cache_key, deps_config,
+      {@manifest_vsn, modules, sources, local_exports, parent, cache_key, cwd, deps_config,
        project_mtime, config_mtime, protocols_and_impls} ->
-        {modules, sources, local_exports, parent, cache_key, deps_config, project_mtime,
+        {modules, sources, local_exports, parent, cache_key, cwd, deps_config, project_mtime,
          config_mtime, protocols_and_impls}
 
       # {vsn, %{module => record}, sources, ...} v22-?
@@ -952,8 +953,8 @@ defmodule Mix.Compilers.Elixir do
     File.mkdir_p!(Path.dirname(manifest))
 
     term =
-      {@manifest_vsn, modules, sources, exports, parents, cache_key, deps_config, project_mtime,
-       config_mtime, protocols_and_impls}
+      {@manifest_vsn, modules, sources, exports, parents, cache_key, File.cwd!(), deps_config,
+       project_mtime, config_mtime, protocols_and_impls}
 
     manifest_data = :erlang.term_to_binary(term, [:compressed])
     File.write!(manifest, manifest_data)

lib/mix/lib/mix/tasks/compile.elixir.ex

@@ -71,7 +71,11 @@ defmodule Mix.Tasks.Compile.Elixir do
     * `--long-verification-threshold N` - sets the "long verification" threshold
       (in seconds) to `N` (see the docs for `Kernel.ParallelCompiler.compile/2`)
     * `--no-verification` - disables code verification, such as unused functions,
-      deprecation warnings, and type checking. It must be used alongside `MIX_DEBUG=1`
+      deprecation warnings, and type checking. It must be used solely for debugging
+      alongside `MIX_DEBUG=1`
+    * `--no-check-cwd` - Elixir stores absolute paths in .beam files, which means rellocating
+      the project root triggers a full build. Pass this option if you don't want the current
+      working directory to be checked
     * `--purge-consolidation-path-if-stale PATH` - deletes and purges modules in the
       given protocol consolidation path if compilation is required
     * `--profile` - if set to `time`, outputs timing information of compilation steps
@@ -109,7 +113,8 @@ defmodule Mix.Tasks.Compile.Elixir do
     profile: :string,
     all_warnings: :boolean,
     verification: :boolean,
-    tracer: :keep
+    tracer: :keep,
+    check_cwd: :boolean
   ]
 
   @impl true
@@ -127,7 +132,7 @@ defmodule Mix.Tasks.Compile.Elixir do
 
     manifest = manifest()
     base = xref_exclude_opts(project[:elixirc_options] || [], project)
-    cache_key = {base, srcs, File.cwd!(), "--no-optional-deps" in args}
+    cache_key = {base, srcs, "--no-optional-deps" in args}
 
     opts =
       base

lib/mix/test/mix/tasks/compile.elixir_test.exs

@@ -118,6 +118,26 @@ defmodule Mix.Tasks.Compile.ElixirTest do
     end)
   end
 
+  test "does not recompiles project if cwd changes and --no-check-pwd is given" do
+    in_fixture("no_mixfile", fn ->
+      Mix.Project.push(MixTest.Case.Sample)
+      assert Mix.Tasks.Compile.Elixir.run(["--verbose"]) == {:ok, []}
+      assert_received {:mix_shell, :info, ["Compiled lib/a.ex"]}
+      Mix.Project.pop()
+
+      old_cwd = File.cwd!()
+
+      in_tmp("new_cwd", fn ->
+        Mix.Project.push(MixTest.Case.Sample)
+        File.cp_r!(old_cwd, File.cwd!())
+
+        purge([A, B])
+        Mix.Task.clear()
+        assert {:noop, _} = Mix.Tasks.Compile.Elixir.run(["--verbose", "--no-check-cwd"])
+      end)
+    end)
+  end
+
   test "recompiles files using Mix.Project if mix.exs changes" do
     in_fixture("no_mixfile", fn ->
       Mix.Project.push(MixTest.Case.Sample, __ENV__.file)