C++20 application failing to compile with OpenOSC using Clang 18.1.1/18.1.2

[johnsonjh]

It does work with older Clang versions, at least through Clang 17.0.6.

See https://gitlab.com/libsir/libsir/-/jobs/6473142110#L91 and https://gitlab.com/libsir/libsir/-/jobs/6473142115#L91 for complete error details.

[johnsonjh]

Verified on a system other than Fedora Rawhide just to be sure it wasn't something Red Hat specific.

Used the Docker image ubuntu:24.04 from Dockerhub (and starting a temporary container docker run --rm -it ubuntu:24.04). Inside the container, I installed packages for libtool autoconf autoconf-archive automake gcc g++ gcc-14 g++-14 clang clang-18 git, and I built and installed OpenOSC master.

Building tests++ target with CXX=g++-13 and CXX=g++-14 both work without problems.

Building tests++ target with CXX=clang++-17 works fine, but CXX=clang++-18 fails with the same symptoms as linked above.

[RupeshPilania]

It fails on FreeBSD 14.1 as well.
[root@localhost ~/godspeed/env/freebsd/ironport/openosc/OpenOSC-1.0.5]# clang --version
FreeBSD clang version 18.1.5 (https://github.com/llvm/llvm-project.git llvmorg-18.1.5-0-g617a15a9eac9)
Target: x86_64-unknown-freebsd14.1
Thread model: posix
InstalledDir: /usr/bin