Initialize git for copied local directory (setuptools-scm)

Author: vpratz

sphinx_polyversion/driver.py

@@ -11,7 +11,7 @@
 from inspect import isawaitable
 from logging import getLogger
 from pathlib import Path
-from subprocess import CalledProcessError
+from subprocess import PIPE, CalledProcessError
 from types import TracebackType
 from typing import (
     TYPE_CHECKING,
@@ -344,6 +344,19 @@ async def build_local(self) -> None:
                     target.parent.mkdir(parents=True, exist_ok=True)
                     if not target.exists():
                         shutil.copy2(source, target, follow_symlinks=False)
+
+                # as .git is not copied, we have to initialize a dummy git repository
+                # in the copied directory (for setuptools-scm)
+                git_init_cmd = ("git", "init", "--initial-branch=dummy")
+                with tempfile.SpooledTemporaryFile(max_size=1024) as f:
+                    process = await asyncio.create_subprocess_exec(
+                        *git_init_cmd, cwd=tmp, stdout=f, stderr=PIPE
+                    )
+                    out, err = await process.communicate()
+                    if process.returncode:
+                        raise CalledProcessError(
+                            process.returncode, " ".join(git_init_cmd), stderr=err
+                        )
             except CalledProcessError:
                 logger.warning(
                     "Could not list un-ignored files using git. Copying full working directory..."

sphinx_polyversion/git.py

@@ -220,7 +220,9 @@ async def _copy_tree(
         )
         out, err = await process.communicate()
         if process.returncode:
-            raise CalledProcessError(process.returncode, " ".join(cmd), stderr=err)
+            raise CalledProcessError(
+                process.returncode, " ".join(git_init_cmd), stderr=err
+            )
 
 
 async def file_exists(repo: Path, ref: GitRef, file: PurePath) -> bool: