"error from receiver: failed to rename .git\objects..." when outputting an existing file in git on Windows

Apologies if this is the wrong place but I believe the issue lies with the output mode of buildkit on Windows when inside a git folder. I have made a simple Dockerfile that demonstrates the issue.

FROM alpine:3.13 AS base

WORKDIR /src
COPY . .
RUN echo "bla" >> /src/bla

FROM scratch AS end
COPY --from=base /src/ /

When I run docker build . --output=. the first time it runs with no issues, creating a file called bla.

However if I run git init, then git add Dockerfile and try building again, I get the following error:

#10 exporting to client
#10 sha256:b60a1292d407630dbb741f28ab6ea4ce3cca872ac28eeee56f4e66a182eca4bc
#10 copying files 11.64kB 0.1s
#10 copying files 25.41kB 0.2s done
#10 ERROR: error from receiver: failed to rename .git\objects\6d\.tmp.943549809 to .git\objects\6d\3ed2f8a87e63b5c06c7a08c2ab46b7b044c0e9: rename .git\objects\6d\.tmp.943549809 .git\objects\6d\3ed2f8a87e63b5c06c7a08c2ab46b7b044c0e9: Access is denied.
------
 > exporting to client:
------
error from receiver: failed to rename .git\objects\6d\.tmp.943549809 to .git\objects\6d\3ed2f8a87e63b5c06c7a08c2ab46b7b044c0e9: rename .git\objects\6d\.tmp.943549809 .git\objects\6d\3ed2f8a87e63b5c06c7a08c2ab46b7b044c0e9: Access is denied.

This does not happen on other platforms, nor does it happen if the directory is not initialised for git or if git is initialised but no files have been added.

Start by reproducing the supplied Dockerfile with docker build . --output=. on Windows, comparing an ordinary directory with a Git-initialized directory after git add Dockerfile. Trace BuildKit's output/export receiver handling for the reported .git\objects rename; done means the second build succeeds without changing behavior on other platforms.