Ninja no longer accepts dupbuild=err

[gruenich]

Describe the bug With the release 1.12, Ninja no longer accepts dupbuild=err, see https://github.com/ninja-build/ninja/pull/2356 It gives a hard error.

[gruenich]

Example:

[   52s] The Meson build system
[   52s] Version: 1.4.0
[   52s] Source dir: /home/abuild/rpmbuild/BUILD/meson-1.4.0/test cases/unit/16 prebuilt static
[   52s] Build dir: /home/abuild/rpmbuild/BUILD/meson-1.4.0/tmpbz6aylpq
[   52s] Build type: native build
[   52s] Project name: prebuilt static lib
[   52s] Project version: undefined
[   52s] C compiler for the host machine: cc (gcc 13.2.1 "cc (SUSE Linux) 13.2.1 20240206 [revision 67ac78caf31f7cb3202177e6428a46d829b70f23]")
[   52s] C linker for the host machine: cc ld.bfd 2.42.0.20240130-4
[   52s] Host machine cpu family: x86_64
[   52s] Host machine cpu: x86_64
[   52s] Library best found: YES
[   52s] Build targets in project: 1
[   52s] 
[   52s] prebuilt static lib undefined
[   52s] 
[   52s]   User defined options
[   52s]     backend: ninja
[   52s]     libdir : lib
[   52s]     prefix : /usr
[   52s] 
[   52s] Found ninja-1.12.0 at /usr/bin/ninja
[   52s] 
[   52s] $ /usr/bin/ninja -w dupbuild=err -d explain
[   52s] stdout:
[   52s] ninja: error: unknown warning flag 'dupbuild=err'

[eli-schwartz]

Duplicate of #13087