LTO issue on CRAN

[osorensen]

I see there is a previous issue on this that has been closed. It does not seem identical, so I open a new issue.

I'm maintaining the package BayesMallows, where we have unit tests of C++ code. In src/RcppExports.cpp, we recently noticed that the line RcppExport SEXP run_testthat_tests(SEXP); changed to RcppExport SEXP run_testthat_tests(void *);. This seems to cause an LTO issue on CRAN. Relevant parts are reproduced below:

** libs
using C++ compiler: ‘g++-13 (GCC) 13.2.0’
using C++17
make[2]: Entering directory '/data/gannet/ripley/R/packages/tests-LTO/BayesMallows/src'
g++-13 -std=gnu++17 -shared -L/usr/local/gcc13/lib64 -L/usr/local/lib64 -o BayesMallows.so RcppExports.o distances.o importance_sampling.o leapandshift.o misc.o missing_data.o mixtures.o pairwise_comparisons.o parameterupdates.o partitionfuns.o rmallows.o run_mcmc.o sample.o smc_calculate_probability.o smc_correction_kernel.o smc_correction_kernel_pseudo.o smc_get_exponent_sum.o smc_get_sample_probabilities.o smc_leap_and_shift_probs.o smc_mallows_new_item_rank.o smc_mallows_new_users.o smc_mallows_new_users_funs.o smc_metropolis_hastings_alpha.o smc_metropolis_hastings_aug_ranking.o smc_metropolis_hastings_rho.o subset.o test-leapandshift.o test-misc.o test-runner.o
RcppExports.cpp:383:17: warning: 'run_testthat_tests' violates the C++ One Definition Rule [-Wodr]
  383 | RcppExport SEXP run_testthat_tests(void *);
      |                 ^
/data/gannet/ripley/R/test-dev/testthat/include/testthat/testthat.h:172:17: note: 'run_testthat_tests' was previously declared here
  172 | extern "C" SEXP run_testthat_tests(SEXP use_xml_sxp) {
      |                 ^
make[2]: Leaving directory '/data/gannet/ripley/R/packages/tests-LTO/BayesMallows/src'
installing to /data/gannet/ripley/R/packages/tests-LTO/Libs/BayesMallows-lib/00LOCK-BayesMallows/00new/BayesMallows/libs

I've tried deleting src/RcppExports.cpp and running Rcpp::compileAttributes() on both Windows and Mac, and both generate run_testthat_tests(void * ) as above.

Any help with this issue would be much appreciated.

[osorensen]

Solved by this Rcpp change: RcppCore/Rcpp#1274