[liblantern CPU compilation ubuntu 22 ] leads to liblantern.so: undefined symbol:

[cregouby]

Current behavior

Trying to build from Rstudio the torch project onto UBUNTU 22.04 CPU with env BUILD_LANTERN=1 leads to the following error at the end of the building log

[100%] Linking CXX shared library liblantern.so
make[3] : on quitte le répertoire « /home/xxx/R/_packages/torch/build-lantern »
[100%] Built target lantern
make[2] : on quitte le répertoire « /home/xxx/R/_packages/torch/build-lantern »
Install the project...
-- Install configuration: ""
-- Installing: /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so
-- Set runtime path of "/home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so" to "$ORIGIN"
-- Installing: /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/include/lantern/lantern.h
-- Installing: /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/include/lantern/types.h
gmake[1] : on quitte le répertoire « /home/xxx/R/_packages/torch/build-lantern »
g++ -std=gnu++17 -shared -L/usr/lib/R/lib -Wl,-Bsymbolic-functions -Wl,-z,relro -o torch.so RcppExports.o amp.o autograd.o backends.o codegen.o contrib.o cuda.o device.o dimname_list.o dtype.o gen-namespace.o generator.o indexing.o ivalue.o jit-compile.o jit-execute.o lantern.o layout.o memory_format.o nn_utils_rnn.o qscheme.o quantization.o reduction.o save.o scalar.o script_module.o stack.o storage.o tensor.o tensor_list.o torch_api.o torch_exports.o trace.o utils.o variable_list.o xptr.o -L/usr/lib/R/lib -lR
ℹ*** Renaming torch lib to torchpkg
"/usr/lib/R/bin/Rscript" "../tools/renamelib.R"
installing to /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/libs
** R
** inst
** byte-compile and prepare package for lazy loading
** help
Avis : ℹ torch failed to start, restart your R session to try again.
ℹ You might need to reinstall torch using `install_torch()`
✖ /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so
-
  /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so:
  undefined symbol:
  _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
Caused by error in `cpp_lantern_init()` at torch/R/lantern_load.R:13:2:
  ! /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so - /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so: undefined symbol: _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
*** installing help indices
*** copying figures
** building package indices
** installing vignettes
** testing if installed package can be loaded from temporary location
Avis : ℹ torch failed to start, restart your R session to try again.
ℹ You might need to reinstall torch using `install_torch()`
✖ /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so
-
  /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so:
  undefined symbol:
  _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
Caused by error in `cpp_lantern_init()` at torch/R/lantern_load.R:13:2:
  ! /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so - /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/00LOCK-torch/00new/torch/lib/liblantern.so: undefined symbol: _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
** checking absolute paths in shared objects and dynamic libraries
** testing if installed package can be loaded from final location
Avis : ℹ torch failed to start, restart your R session to try again.
ℹ You might need to reinstall torch using `install_torch()`
✖ /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/torch/lib/liblantern.so -
  /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/torch/lib/liblantern.so:
  undefined symbol:
  _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
Caused by error in `cpp_lantern_init()` at torch/R/lantern_load.R:13:2:
  ! /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/torch/lib/liblantern.so - /home/xxx/R/x86_64-pc-linux-gnu-library/4.3/torch/lib/liblantern.so: undefined symbol: _ZN2at4_ops25reflection_pad1d_backward4callERKNS_6TensorES4_N3c108ArrayRefINS5_6SymIntEEE
** testing if installed package keeps a record of temporary installation path
* DONE (torch)

Expected behavior

correct build so I can run tests part of my Pull Request before submitting...

Context

Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 22.04.3 LTS

Matrix products: default
BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.10.0 
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.10.0

locale:
 [1] LC_CTYPE=fr_FR.UTF-8      
 [2] LC_NUMERIC=C              
 [3] LC_TIME=fr_FR.UTF-8       
 [4] LC_COLLATE=fr_FR.UTF-8    
 [5] LC_MONETARY=fr_FR.UTF-8   
 [6] LC_MESSAGES=fr_FR.UTF-8   
 [7] LC_PAPER=fr_FR.UTF-8      
 [8] LC_NAME=C                 
 [9] LC_ADDRESS=C              
[10] LC_TELEPHONE=C            
[11] LC_MEASUREMENT=fr_FR.UTF-8
[12] LC_IDENTIFICATION=C       

time zone: Europe/Paris
tzcode source: system (glibc)

attached base packages:
character(0)

other attached packages:
[1] torch_0.11.0.9002

loaded via a namespace (and not attached):
 [1] digest_0.6.33     methods_4.3.1    
 [3] coro_1.0.3        fastmap_1.1.1    
 [5] xfun_0.40         bit_4.0.5        
 [7] magrittr_2.0.3    bspm_0.5.1       
 [9] knitr_1.44        htmltools_0.5.6  
[11] rmarkdown_2.25    bit64_4.0.5      
[13] utils_4.3.1       ps_1.7.5         
[15] cli_3.6.1         processx_3.8.2   
[17] callr_3.7.3       graphics_4.3.1   
[19] grDevices_4.3.1   stats_4.3.1      
[21] compiler_4.3.1    base_4.3.1       
[23] rstudioapi_0.15.0 tools_4.3.1      
[25] evaluate_0.21     yaml_2.3.7       
[27] Rcpp_1.0.11       rlang_1.1.1      
[29] datasets_4.3.1   

[dfalbel]

Hi @cregouby,

Thanks for reporting!

I believe this caused by a mismatch between LibLantern's expected LibTorch and the one installed in the build-lantern directory. What happens if you erase the build-lantern/libtorch and try to rebuild? Do you still get the same errors?

[cregouby]

Hello @dfalbel
Thanks a lot for the hint, as yes I had unexpected file in the "lantern/build" folder. Plus I was using the RStudio "Install" button, that, in the case of {torch} is the wrong way to proceed.
Now, with a cleaned install folder plus using the proper procedure documented in CONTRIBUTION.md, build is fine !