Ninja Error: cannot find LLVMgold.so

[yangocean-sudo]

OS: CentOS Linux release 7.9.2009 (Core)
CPU: Intel(R) Xeon(R) Gold 6342 CPU @ 2.80GHz
GPU: NVIDIA GeForce RTX 4080
Python: Python 3.12.4 | packaged by Anaconda, Inc. |
LLVM: 10.0.0

Dr.Jit: 0.4.6
Mitsuba: 3.5.2
Is custom build? Just follow the instruction
The CXX compiler identification is Clang 10.0.0
The C compiler identification is Clang 10.0.0

Variants:
scalar_rgb
scalar_spectral
cuda_ad_rgb
llvm_ad_rgb

Hi, I'm following the instruction to compile the Mitsuba3 in Linux and conda environment. Here is the result of cmake -GNinja .. :

-- The CXX compiler identification is Clang 10.0.0
-- The C compiler identification is Clang 10.0.0
-- Check for working CXX compiler: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang++
-- Check for working CXX compiler: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Check for working C compiler: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang
-- Check for working C compiler: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Mitsuba v3.5.2 
-- Mitsuba: setting build type to 'Release' as none was specified.
-- Mitsuba: targeting the native CPU architecture (specify MI_NATIVE_FLAGS to change this).
-- Found Python: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/python3.1 (found version "3.12.4") found components: Interpreter Development 
-- Looking for C++ include pybind11/pybind11.h
-- Looking for C++ include pybind11/pybind11.h - not found
-- pybind11 v2.10.1 
-- Performing Test HAS_FLTO
-- Performing Test HAS_FLTO - Failed
-- Performing Test HAS_FLTO_THIN
-- Performing Test HAS_FLTO_THIN - Failed
-- Mitsuba: building the following variants:
--  * scalar_rgb
--  * scalar_spectral
--  * cuda_ad_rgb
--  * llvm_ad_rgb
-- Dr.Jit v0.4.6 
-- Dr.Jit: building the CUDA & LLVM JIT backend.
-- Dr.Jit-Core: LLVM will be loaded dynamically at runtime.
-- Dr.Jit-Core: CUDA will be loaded dynamically at runtime.
-- Dr.Jit-Core: OptiX support enabled.
-- Dr.Jit-Core: OptiX debug and validation flags disabled.
-- Dr.Jit: building the autodiff backend.
-- Dr.Jit: building the Python plugin.
-- Found Git: /usr/bin/git (found version "1.8.3.1") 
-- CLANG detected
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Configure ILMBASE Version: 2.5.5 Lib API: 25.0.4
-- Check if compiler accepts -pthread
-- Check if compiler accepts -pthread - yes
-- Looking for include file ucontext.h
-- Looking for include file ucontext.h - found
-- Performing Test ILMBASE_HAVE_CONTROL_REGISTER_SUPPORT
-- Performing Test ILMBASE_HAVE_CONTROL_REGISTER_SUPPORT - Success
-- Looking for include file semaphore.h
-- Looking for include file semaphore.h - found
-- Looking for sem_init in pthread
-- Looking for sem_init in pthread - found
-- Configure OpenEXR Version: 2.5.5 Lib API: 25.0.4
-- Found ZLIB: /usr/lib64/libz.so (found version "1.2.7") 
-- Performing Test OPENEXR_IMF_HAVE_SYSCONF_NPROCESSORS_ONLN
-- Performing Test OPENEXR_IMF_HAVE_SYSCONF_NPROCESSORS_ONLN - Success
-- Performing Test OPENEXR_IMF_HAVE_GCC_INLINE_ASM_AVX
-- Performing Test OPENEXR_IMF_HAVE_GCC_INLINE_ASM_AVX - Success
-- The ASM compiler identification is Clang
-- Found assembler: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang
-- Performing Test HAVE_LD_VERSION_SCRIPT
-- Performing Test HAVE_LD_VERSION_SCRIPT - Success
-- Looking for stddef.h
-- Looking for stddef.h - found
-- Looking for stdlib.h
-- Looking for stdlib.h - found
-- Performing Test __CxxFlag__fno_threadsafe_statics
-- Performing Test __CxxFlag__fno_threadsafe_statics - Success
-- Performing Test __CxxFlag__fno_semantic_interposition
-- Performing Test __CxxFlag__fno_semantic_interposition - Success
-- Performing Test __CxxFlag__fmerge_all_constants
-- Performing Test __CxxFlag__fmerge_all_constants - Success
-- Performing Test __CxxFlag__fno_enforce_eh_specs
-- Performing Test __CxxFlag__fno_enforce_eh_specs - Failed
-- Could NOT find OpenMP_C (missing: OpenMP_C_FLAGS OpenMP_C_LIB_NAMES) 
-- Could NOT find OpenMP_CXX (missing: OpenMP_CXX_FLAGS OpenMP_CXX_LIB_NAMES) 
-- Could NOT find OpenMP (missing: OpenMP_C_FOUND OpenMP_CXX_FOUND) 
-- Tests are disabled. Set FASTFLOAT_TEST to ON to run tests.
-- Mitsuba: using OptiX for GPU ray tracing.
-- Mitsuba: using Embree for CPU ray tracing.
-- Mitsuba: OptiX debug and validation flags disabled.
-- Check if the system is big endian
-- Searching 16 bit integer
-- Looking for sys/types.h
-- Looking for sys/types.h - found
-- Looking for stdint.h
-- Looking for stdint.h - found
-- Check size of unsigned short
-- Check size of unsigned short - done
-- Using unsigned short
-- Check if the system is big endian - little endian
-- Found Sphinx: /opt/apps/apps/binapps/anaconda3/2023.09/bin/sphinx-build  
CMake Warning at CMakeLists.txt:467 (message):
  

  Created a default 'mitsuba.conf' configuration file.  You will
  probably want to edit this file to specify the desired configurations
  before starting to compile.


-- Configuring done
-- Generating done
-- Build files have been written to: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/scratch/mitsuba3/build

And after I run the command ninja, I faced an error:

[11/1182] Linking CXX shared library libnanothread.so
FAILED: libnanothread.so 
: && /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/clang++ -fPIC -stdlib=libc++ -I/mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/include/c++/v1 -fcolor-diagnostics -O3 -DNDEBUG -flto=thin  -stdlib=libc++ -L/mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/lib -lc++ -lc++abi -shared -Wl,-soname,libnanothread.so -o libnanothread.so ext/drjit/ext/drjit-core/ext/nanothread/CMakeFiles/nanothread.dir/src/queue.cpp.o ext/drjit/ext/drjit-core/ext/nanothread/CMakeFiles/nanothread.dir/src/nanothread.cpp.o  -Wl,-rpath,:::::::::::::::::::::::: && :
/usr/bin/ld: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/../lib/LLVMgold.so: error loading plugin: /mnt/iusers01/fse-ugpgt01/compsci01/b41153yc/.conda/envs/mitsuba/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory
clang-10: error: linker command failed with exit code 1 (use -v to see invocation)
[60/1182] Building CXX object ext/drjit/src/python/CMakeFiles/drjit-python.dir/bind_llvm_ad.cpp.o
ninja: build stopped: subcommand failed.

I searched that conda doesn't have LLVMgold and can use the lld package instead. I've tried it but still faced other errors, so I'm wondering if installing lld is a right choice or if I'm missing some important content. Thank you.

[merlinND]

Hello @yangocean-sudo,

I've never used conda, but as you've noticed it seems that LLVM Gold is not part of the LLVM package (conda-forge/llvmdev-feedstock#172).
How about installing clang / LLVM outside of Conda? You should still be able to use Conda for the Python and Python packages management.