floss: refuse to build if bootstrapped for a different project

Stop the build if the bootstrapped project is different than the one
building, and warn the user to rerun the bootstrap.

Bug: 247004173
Test: ./build.py
Change-Id: Ia98d28d55014fcb9ff8e484e078e329903b071a9

1 files changed, 4 insertions, 0 deletions

diff --git a/build.py b/build.py
index f423de55be..994e00a9da 100755
--- a/build.py
+++ b/build.py
@@ -192,10 +192,14 @@ class HostBuild():
         # Output and platform directories are based on bootstrap
         self.output_dir = os.path.join(self.bootstrap_dir, 'output')
         self.platform_dir = os.path.join(self.bootstrap_dir, 'staging')
+        self.bt_dir = os.path.join(self.platform_dir, 'bt')
         self.sysroot = self.args.sysroot
         self.libdir = self.args.libdir
         self.install_dir = os.path.join(self.output_dir, 'install')
 
+        assert os.path.samefile(self.bt_dir,
+                                os.path.dirname(__file__)), "Please rerun bootstrap for the current project!"
+
         # If default target isn't set, build everything
         self.target = 'all'
         if hasattr(self.args, 'target') and self.args.target: