CMAKE_NINJA_OUTPUT_PATH_PREFIXΒΆ
Added in version 3.6.
Tell the Ninja Generators to add a prefix to every output path in
build.ninja. A trailing slash is appended to the prefix, if missing.
This is useful when the generated ninja file is meant to be embedded as a
subninja file into a super ninja project. For example, the command:
cd super-build-dir &&
cmake -G Ninja -S /path/to/src -B sub -DCMAKE_NINJA_OUTPUT_PATH_PREFIX=sub/
# ^^^---------- these match -----------^^^
generates a build directory with its top-level (CMAKE_BINARY_DIR)
in super-build-dir/sub. The path to the build directory ends in the
output path prefix. This makes it suitable for use in a separately-written
super-build-dir/build.ninja file with a directive like this:
subninja sub/build.ninja
The auto-regeneration rule in super-build-dir/build.ninja must
have an order-only dependency on sub/build.ninja.
Added in version 3.27: The Ninja Multi-Config generator supports this variable.
Note
When CMAKE_NINJA_OUTPUT_PATH_PREFIX is set, the project generated
by CMake cannot be used as a standalone project. No default targets
are specified.
The value of CMAKE_NINJA_OUTPUT_PATH_PREFIX must match one or more
path components at the end of CMAKE_BINARY_DIR, or the
behavior is undefined. However, this requirement is not checked
automatically.