Bug#1125733: llvm-toolchain-21: FTBFS: ADD_LIBRARY called with SHARED option but the target platform does not support dynamic linking.

[Fabian Grünbichler]

On Fri, 16 Jan 2026 19:03:25 +0000 Santiago Vila <sanvila at debian.org> wrote:
> Package: src:llvm-toolchain-21
> Version: 1:21.1.8-1
> Severity: serious
> Tags: ftbfs forky sid
> 
> Dear maintainer:
> 
> During a rebuild of all packages in unstable, this package failed to build.
> 
> Below you will find the last part of the build log (probably the most
> relevant part, but not necessarily). If required, the full build log
> is available here:
> 
> https://people.debian.org/~sanvila/build-logs/202601/

FWIW, I think this is caused by the recent cmake 4 upload to unstable,
as the working (pre-cmake-4) build in sid also has those lines, but
followed by:

> This warning is for project developers.  Use -Wno-dev to suppress it.

and it is classified as "CMake Warning (dev)" there instead of as "CMake
Error" like in the cmake-4 log.

> 
> About the archive rebuild: The build was made on virtual machines from AWS,
> using sbuild and a reduced chroot with only build-essential packages.
> 
> If you cannot reproduce the bug please contact me privately, as I
> am willing to provide ssh access to a virtual machine where the bug is
> fully reproducible.
> 
> If this is really a bug in one of the build-depends, please use
> reassign and add an affects on src:llvm-toolchain-21, so that this is still
> visible in the BTS web page for this package.
> 
> Thanks.
> 
> --------------------------------------------------------------------------------
> [...]
> -- Could NOT find ZLIB (missing: ZLIB_LIBRARY ZLIB_INCLUDE_DIR) 
> -- Could NOT find zstd (missing: zstd_LIBRARY zstd_INCLUDE_DIR) 
> -- Found LibXml2: /usr/lib/x86_64-linux-gnu/libxml2.so (found version "2.15.1")
> -- Found CURL: /usr/lib/x86_64-linux-gnu/libcurl.so (found version "8.18.0")
> CMake Error at /<<PKGBUILDDIR>>/build-llvm/tools/clang/stage2-bins/lib/cmake/llvm/LLVMExports.cmake:1531 (add_library):
>   ADD_LIBRARY called with SHARED option but the target platform does not
>   support dynamic linking.
> Call Stack (most recent call first):
>   /<<PKGBUILDDIR>>/build-llvm/tools/clang/stage2-bins/lib/cmake/llvm/LLVMConfig.cmake:382 (include)
>   /<<PKGBUILDDIR>>/compiler-rt/cmake/Modules/CompilerRTUtils.cmake:312 (find_package)
>   CMakeLists.txt:29 (load_llvm_config)
> 
> 
> -- Configuring incomplete, errors occurred!
> make[1]: *** [debian/rules:1304: build-wasm/compiler-rt-wasm32] Error 1
> make[1]: Leaving directory '/<<PKGBUILDDIR>>'
> make: *** [debian/rules:859: binary] Error 2
> dpkg-buildpackage: error: debian/rules binary subprocess failed with exit status 2
> --------------------------------------------------------------------------------
> 
> 
>