Bug#1121222: LLVM 21 ftbfs on hurd-amd64

[Samuel Thibault]

Hello,

Matthias Klose, le dim. 23 nov. 2025 07:05:44 +0100, a ecrit:
> there's a first build log on hurd-amd64,

There are earlier build logs on the -19 version:

https://buildd.debian.org/status/fetch.php?pkg=llvm-toolchain-19&arch=hurd-amd64&ver=1%3A19.1.7-17&stamp=1763842985&raw=0


-- Compiler-RT supported architectures: x86_64
-- Failed to find compiler-rt builtins library for x86_64-unknown-hurd-gnu0.9
CMake Error at /build/reproducible-path/llvm-toolchain-19-19.1.7/compiler-rt/cmake/Modules/AddCompilerRT.cmake:276 (message):
  Cannot find builtins library for the target architecture
Call Stack (most recent call first):
  /build/reproducible-path/llvm-toolchain-19-19.1.7/compiler-rt/lib/orc/CMakeLists.txt:135 (add_compiler_rt_runtime)

I have not yet taken the time to investigate more closely why liborc
fails to find compiler-rt. Possibly it's simply looking for asan runtime
symbols or such, which are not ported to GNU/Hurd yet. What I have been
doing in unreleased so far is to just disable liborc in a crude way:

disable orc by hand for now until ORC_SUPPORTED_OS is fixed
Index: llvm-toolchain-21-21.1.5/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
===================================================================
--- llvm-toolchain-21-21.1.5.orig/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
+++ llvm-toolchain-21-21.1.5/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
@@ -116,7 +116,7 @@ if (UNIX)
   if (OS_NAME MATCHES "Linux")
     set(ALL_ORC_SUPPORTED_ARCH ${X86_64} ${ARM64} ${ARM32} ${PPC64} ${LOONGARCH64})
   else()
-    set(ALL_ORC_SUPPORTED_ARCH ${X86_64} ${ARM64} ${ARM32})
+    set(ALL_ORC_SUPPORTED_ARCH ${ARM64} ${ARM32})
   endif()
 endif()

> dh_install --list-missing
> dh_install: warning: Please use dh_missing --list-missing/--fail-missing
> instead
> dh_install: warning: This feature will be removed in compat 12.
> dh_install: warning: Cannot find (any matches for)
> "usr/lib/llvm-21/lib/clang/21*/lib/*/*clang_rt*" (tried in ., debian/tmp)
> 
> dh_install: warning: libclang-rt-21-dev missing files:
> usr/lib/llvm-21/lib/clang/21*/lib/*/*clang_rt*
> dh_install: error: missing files, aborting
> make[1]: *** [debian/rules:1906: override_dh_install] Error 255
> 
> please check, if the compiler-rt is usable on hurd-amd64,

Yes, its testsuite passes fine:

Total Discovered Tests: 311
  Unsupported      : 151 (48.55%)
  Passed           : 159 (51.13%)
  Expectedly Failed:   1 (0.32%)

> then we can re-enable it.

Yes, please. Better rather disable just liborc:

ifneq (,$(filter $(DEB_HOST_ARCH),hurd-amd64))
  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_BUILD_ORC=OFF
endif

I have submitted
https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/-/merge_requests/200
doing that in the 21 branch.

Samuel