`cargo build` fails with `not a reparse point` error

[Lynnesbian]

I built a Docker image based on msys2-docker and ran it with docker container run -it --entrypoint bash -v ../..:/root/.wine/drive_c/msys64/home/root/app:Z app. Commands like ls app and msys2 -c "ls app" work fine.

cding into app and running cargo build produces the following error:

error: failed to determine package fingerprint for build script for app v0.1.0 (C:\msys64\home\root\app)

Caused by:
  failed to determine the most recently modified file in C:\msys64\home\root\app

Caused by:
  failed to determine list of files in C:\msys64\home\root\app

Caused by:
  File or directory is not a reparse point. (os error 4390)

If I create a copy of the app directory, I can run cargo build from there:

$ cp -r app app2
$ cd app2
$ msys2 -c "cargo build"
   Compiling proc-macro2 v1.0.106
   Compiling unicode-ident v1.0.24
   Compiling quote v1.0.45

# ... successful build output ...

I don't know if this is a bug in MSYS2, Docker, Wine, Rust/Cargo, or something else entirely. Apologies if this is the wrong place to report this.