test compilation fails on Alpine Linux

[bastistician]

Using the current CRAN versions of all involved packages (including 'rstanarm' 2.32.2, 'rstan' 2.32.7, 'StanHeaders' 2.39.1), R CMD check gives:

  ══ Failed tests ════════════════════════════════════════════════════════════════
  ── Error ('test_stan_functions.R:64:1'): (code run outside of `test_that()`) ───
  Error in `expose_stan_functions(stanc_ret, rebuild = TRUE, verbose = TRUE)`: Compilation failed!
  Backtrace:
      ▆
   1. └─rstan::expose_stan_functions(stanc_ret, rebuild = TRUE, verbose = TRUE) at test_stan_functions.R:64:1

Unfortunately, the check log is not very helpful, not only because of the 'testthat' camouflage but also because rstan::expose_stan_functions runs Rcpp::sourceCpp() in try(silent=TRUE), hiding the actual error. So I inserted

trace(expose_stan_functions, quote(try <- function(..., silent) base::try(...)))

just before the expose_stan_functions call in the test script to remove its silence.

This reveals that building the shared library

g++ -std=gnu++17 -shared -L/usr/local/lib -o sourceCpp_2.so file19b9609a5bbf.o /mnt/runner/lib/rstan/lib//libStanServices.a -L/mnt/runner/lib/StanHeaders/lib/ -lStanHeaders -L/mnt/runner/lib/RcppParallel/lib/ -ltbb

succeeds, but Rcpp::sourceCpp() then fails from loading the module (source(scriptPath, local = env)):

Error in dyn.load("/tmp/RtmpoaocOG/sourceCpp-x86_64-pc-linux-musl-1.1.2/sourcecpp_49ad49147921/sourceCpp_2.so") : 
  unable to load shared object '/tmp/RtmpoaocOG/sourceCpp-x86_64-pc-linux-musl-1.1.2/sourcecpp_49ad49147921/sourceCpp_2.so':
  Error loading shared library libtbb.so: No such file or directory

Obviously, system.file("lib", "libtbb.so", package = "RcppParallel") is available, but not normally in the runtime search path, and there is no system installation of TBB.

FWIW, I can make this test compilation work by setting

Sys.setenv(PKG_LIBS = paste0("-Wl,-rpath,", RcppParallel::tbbLibraryPath()))

before expose_stan_functions().

[jgabry]

Thanks for reporting this. I just opened PR #661. I think the problem is in the rstan package. rstanplugin sets tbb_libs <- "-ltbb" with no rpath, so any user on Alpine Linux will probably hit the same error, so we'll also fix it there.

[bastistician]

Thanks! While at it: I don't know why rstan::expose_stan_functions() chose to wrap compilation inside try(silent=TRUE), but it would really help if errors were visible.