cmake tries to install libfmt

[Eragonfr]

I'm trying to fix the new archlinux pioneer package. All commands are taken from their build script here.
https://gitlab.archlinux.org/archlinux/packaging/packages/pioneer

Observed behaviour

After build cmake --install tries to install libfmt in the system

Expected behaviour

libfmt is not installed by cmake

Steps to reproduce

Build with

cmake -S . -B build -G Ninja \
  -D CMAKE_INSTALL_PREFIX:PATH=/usr/local \ # Changed the prefix path because I don't want to put non-packaged stuff in /usr
  -D PIONEER_DATA_DIR:PATH=/usr/local/share/pioneer/data \
  -D USE_SYSTEM_LIBGLEW:BOOL=ON \
  -D USE_SYSTEM_LIBLUA:BOOL=ON \
  -D CMAKE_EXPORT_COMPILE_COMMANDS=1 \
  -Wno-dev

cmake --build build -j 10 --target all build-data

Install with

cmake --install build --strip

My pioneer version (and OS): Sources from release 20240314 on ArtixLinux (Arch based, the only difference is the init)

EDIT: This is the same on Archlinux official build servers.

[pcercuei]

Setting -DFMT_INSTALL=OFF should work.
(but this probably should be forced in the main CMake script, yes)

[Eragonfr]

It works, thank you.

[impaktor]

We want to keep this open until someone PRs the suggested change, I assume