It seems there is another meson (0.57.0) regression preventing clang from
building systemd with --optimization=3 -Db_lto=true
By analogy with https://github.com/google/oss-fuzz/pull/5199 let's just switch
to 0.56.2 for the time being
# support all the features we need (like --optimization=). Since the build-dep
# command above installs the distro versions, let's install the pip ones just
# locally and add the local bin directory to the $PATH.
-pip3 install --user -U meson ninja
+pip3 install --user -U meson==0.56.2 ninja
export PATH="$HOME/.local/bin:$PATH"
$CC --version