[gnome-builder] cargo: cd into project dir rather than use --manifest-path

[Christian Hergert <chergert src gnome org>]

commit 8b56b7b90ccaec8169d00a0c17f47f650a75987d
Author: Nathaniel McCallum <npmccallum redhat com>
Date:   Sun Mar 1 14:24:57 2020 -0500

    cargo: cd into project dir rather than use --manifest-path
    
    Using --manifest-path ignores the settings in .cargo/config.

 src/plugins/cargo/cargo_plugin.py | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)
---
diff --git a/src/plugins/cargo/cargo_plugin.py b/src/plugins/cargo/cargo_plugin.py
index d16bca58c..4c228a783 100644
--- a/src/plugins/cargo/cargo_plugin.py
+++ b/src/plugins/cargo/cargo_plugin.py
@@ -87,7 +87,7 @@ class CargoPipelineAddin(Ide.Object, Ide.PipelineAddin):
         if project_file.get_basename() != 'Cargo.toml':
             project_file = project_file.get_child('Cargo.toml')
 
-        cargo_toml = project_file.get_path()
+        project_dir = os.path.dirname(project_file.get_path())
         config = pipeline.get_config()
         builddir = pipeline.get_builddir()
         runtime = config.get_runtime()
@@ -99,19 +99,17 @@ class CargoPipelineAddin(Ide.Object, Ide.PipelineAddin):
         # Fetch dependencies so that we no longer need network access
         fetch_launcher = pipeline.create_launcher()
         fetch_launcher.setenv('CARGO_TARGET_DIR', builddir, True)
+        fetch_launcher.set_cwd(project_dir)
         fetch_launcher.push_argv(cargo)
         fetch_launcher.push_argv('fetch')
-        fetch_launcher.push_argv('--manifest-path')
-        fetch_launcher.push_argv(cargo_toml)
         self.track(pipeline.attach_launcher(Ide.PipelinePhase.DOWNLOADS, 0, fetch_launcher))
 
         # Now create our launcher to build the project
         build_launcher = pipeline.create_launcher()
         build_launcher.setenv('CARGO_TARGET_DIR', builddir, True)
+        build_launcher.set_cwd(project_dir)
         build_launcher.push_argv(cargo)
         build_launcher.push_argv('build')
-        build_launcher.push_argv('--manifest-path')
-        build_launcher.push_argv(cargo_toml)
         build_launcher.push_argv('--message-format')
         build_launcher.push_argv('human')
 
@@ -136,10 +134,9 @@ class CargoPipelineAddin(Ide.Object, Ide.PipelineAddin):
 
         clean_launcher = pipeline.create_launcher()
         clean_launcher.setenv('CARGO_TARGET_DIR', builddir, True)
+        clean_launcher.set_cwd(project_dir)
         clean_launcher.push_argv(cargo)
         clean_launcher.push_argv('clean')
-        clean_launcher.push_argv('--manifest-path')
-        clean_launcher.push_argv(cargo_toml)
 
         build_stage = Ide.PipelineStageLauncher.new(context, build_launcher)
         build_stage.set_name(_("Building project"))