CURL missing LTO?

[Undrog]

I've been studying this project as a learning exercise, and I think I stumbled upon a couple of issues, but I'm not confident so I'm starting with a discussion and not a bug report.

In the Dockerfile, the following command is run:
cmake . -D ENABLE_ARES=ON CURL_LTO=ON -D CURL_USE_OPENSSL=ON... (truncated)

Output (plain) from bake:

#49 [builder 19/66] RUN cmake . -D ENABLE_ARES=ON CURL_LTO=ON -D CURL_USE_OPENSSL=ON -D CURL_BROTLI=ON -D CURL_ZSTD=ON -D BUILD_SHARED_LIBS=ON -D CMAKE_BUILD_TYPE:STRING="Release" -D CMAKE_C_FLAGS_RELEASE:STRING="-O3 -flto="$(nproc)" -pipe"
#49 0.308 CMake Warning:
#49 0.308   Ignoring extra path from command line:
#49 0.308 
#49 0.308    "CURL_LTO=ON"
#49 0.308 
#49 0.308 

I think -D is missing before CURL_LTO=ON.