Add compiler path to $PATH and $CRYSTAL_EXEC_PATH for subcommands

.github/workflows/mingw-w64.yml

@@ -148,3 +148,5 @@ jobs:
         run: |
           export CRYSTAL_SPEC_COMPILER_BIN="$(which crystal.exe)"
           make -o .build/crystal.exe primitives_spec # we know the compiler is fresh; do not rebuild it here
+        env:
+          SPEC_FLAGS: --tag=~external_commands # skip exec_external_command spec because it doesn't work with this setup

bin/crystal

@@ -186,6 +186,11 @@ case "$(uname -s)" in
     ;;
 esac
 
+# CRYSTAL_EXEC_PATH determines the location of the `crystal` program for external
+# compiler commands.
+CRYSTAL_EXEC_PATH="$SCRIPT_ROOT"
+export CRYSTAL_EXEC_PATH
+
 if [ -x "$CRYSTAL_DIR/${CRYSTAL_BIN}" ]; then
   __warning_msg "Using compiled compiler at ${CRYSTAL_DIR#"$PWD/"}/${CRYSTAL_BIN}"
   exec "$CRYSTAL_DIR/${CRYSTAL_BIN}" "$@"

spec/primitives/external_command_spec.cr

@@ -3,32 +3,40 @@
 require "../support/tempfile"
 
 describe "Crystal::Command" do
-  it "exec external commands", tags: %w[slow] do
-    with_temp_executable "crystal-external" do |path|
+  it "exec external commands", tags: %w[slow external_commands] do
+    with_temp_executable "crystal-external" do |command_path|
+      compiler_path = File.expand_path(ENV["CRYSTAL_SPEC_COMPILER_BIN"]? || "bin/crystal")
+
       with_tempfile "crystal-external.cr" do |source_file|
         File.write source_file, <<-CRYSTAL
-          puts ENV["CRYSTAL"]?
+          puts Process.find_executable("crystal")
+          puts ENV["CRYSTAL_EXEC_PATH"]?
           puts PROGRAM_NAME
           puts ARGV
           CRYSTAL
 
-        Process.run(ENV["CRYSTAL_SPEC_COMPILER_BIN"]? || "bin/crystal", ["build", source_file, "-o", path])
+        Process.run(compiler_path, ["build", source_file, "-o", command_path], error: :inherit)
       end
 
-      File.exists?(path).should be_true
+      File.exists?(command_path).should be_true
 
-      process = Process.new(ENV["CRYSTAL_SPEC_COMPILER_BIN"]? || "bin/crystal",
+      process = Process.new(compiler_path,
         ["external", "foo", "bar"],
-        output: :pipe,
-        env: {"PATH" => {ENV["PATH"], File.dirname(path)}.join(Process::PATH_DELIMITER)}
+        output: :pipe, error: :pipe,
+        env: {"PATH" => {ENV["PATH"], File.dirname(command_path)}.join(Process::PATH_DELIMITER)}
       )
+
       output = process.output.gets_to_end
+      error = process.error.gets_to_end
       status = process.wait
-      status.success?.should be_true
-      lines = output.lines
-      lines[0].should match /crystal/
-      lines[1].should match /crystal-external/
-      lines[2].should eq %(["foo", "bar"])
+      status.success?.should be_true, failure_message: "Running external subcommand failed.\nstderr:\n#{error}\nstdout:\n#{output}"
+
+      output.lines.should eq [
+        compiler_path,
+        File.dirname(compiler_path),
+        command_path,
+        %(["foo", "bar"]),
+      ]
     end
   end
 end

src/compiler/crystal/command.cr

@@ -132,7 +132,19 @@ class Crystal::Command
         error "file '#{command}' does not exist"
       elsif external_command = Process.find_executable("crystal-#{command}")
         options.shift
-        Process.exec(external_command, options, env: {"CRYSTAL" => Process.executable_path})
+
+        crystal_exec_path = ENV["CRYSTAL_EXEC_PATH"]?
+        unless crystal_exec_path
+          if executable_path = Process.executable_path
+            crystal_exec_path = File.dirname(executable_path)
+          end
+        end
+        path = [crystal_exec_path, ENV["PATH"]?].compact!.join(Process::PATH_DELIMITER)
+
+        Process.exec(external_command, options, env: {
+          "PATH"              => path,
+          "CRYSTAL_EXEC_PATH" => crystal_exec_path,
+        })
       else
         error "unknown command: #{command}"
       end

src/compiler/crystal/command/spec.cr

@@ -95,7 +95,12 @@ class Crystal::Command
 
     output_filename = Crystal.temp_executable "spec"
 
-    ENV["CRYSTAL_SPEC_COMPILER_BIN"] ||= Process.executable_path
+    ENV["CRYSTAL_SPEC_COMPILER_BIN"] ||= if crystal_exec_path = ENV["CRYSTAL_EXEC_PATH"]?
+                                           File.join(crystal_exec_path, "crystal")
+                                         else
+                                           Process.executable_path
+                                         end
+
     compiler.compile sources, output_filename
     report_warnings
     execute output_filename, options, compiler, error_on_exit: warnings_fail_on_exit?