Single-threaded OpenBLAS for pycolmap

app.py

@@ -21,6 +21,10 @@ from pathlib import Path
 APP_DIR = Path(__file__).parent.resolve()
 sys.path.insert(0, str(APP_DIR))
 
+# pycolmap's bundled OpenBLAS segfaults ("Bad memory unallocation") when many matcher
+# threads each spin up a multi-threaded BLAS; keep BLAS single-threaded.
+os.environ["OPENBLAS_NUM_THREADS"] = "1"
+os.environ.setdefault("OMP_NUM_THREADS", "4")
 os.environ.setdefault("TORCH_CUDA_ARCH_LIST", "12.0")
 os.environ.setdefault("MAX_JOBS", str(min(32, (os.cpu_count() or 8))))