components/ovmf.bst failed to build, a git submodule was not properly staged

Context

I try to build components/ovmf.bst(hash 5e81e52e) at 41c1b8f3 on my machine. But it failed to build. I run bst shell -b components/ovmf.bst to get into the builddir. I found BaseTools/Source/C/BrotliCompress/brotli/ is empty. The directory should contain the submodule from github:google/brotli.git. The exact same submodule at directory MdeModulePkg/Library/BrotliCustomDecompressLib/brotli was properly checked out.

• Buildstream tested tag 2.0.0 and branch nanonyme/nanonyme/downloadable-source.
• buildbox-run-bubblewrap at 0.64
• buildbox-{common,fuse} at 0.65

Description

It is absolutely not an issue of freedesktop-sdk. But I did not go deep into the Builstream source code, so I report it here first.

Acceptance Criteria

Both git submodules are properly checked out and build of components/ovmf.bst succeeds.