use setuptools_scm provided version

scripts/build.py

@@ -1,7 +1,5 @@
 import argparse
-import importlib.util
 import pathlib
-import textwrap
 from subprocess import STDOUT, check_call
 
 path = pathlib.Path(__file__).parent.absolute()
@@ -25,22 +23,8 @@ args = parser.parse_args()
 
 (dvc / "utils" / "build.py").write_text(f'PKG = "{args.pkg}"')
 
-# Autogenerate version, similar to what we do in setup.py
-spec = importlib.util.spec_from_file_location(
-    "dvc.version", dvc / "version.py"
-)
-dvc_version = importlib.util.module_from_spec(spec)
-spec.loader.exec_module(dvc_version)
-version = dvc_version.__version__
-
-(dvc / "version.py").write_text(
-    textwrap.dedent(
-        f"""\
-        # AUTOGENERATED at build time by scripts/build.py
-        __version__ = "{version}"
-    """
-    )
-)
+if not (dvc / "_dvc_version.py").exists():
+    raise Exception("no version info found")
 
 check_call(
     ["python", "build.py"],