Rcpp 1.1.1 could not be installed on FreeBSD

[jszhao]

I have R 4.5.2 installed on FreeBSD 15.0, and when I install Rcpp 1.1.1 using C++ compiler: ‘FreeBSD clang version 19.1.7, it gives the following error message:

/opt/R/library/00LOCK-Rcpp/00new/Rcpp/libs/Rcpp.so: Undefined symbol "backtrace"

If I install Rcpp 1.1.1 using C++ compiler: ‘g++14 (FreeBSD Ports Collection) 14.2.0’, it gives the following error message:

/opt/R/library/00LOCK-Rcpp/00new/Rcpp/libs/Rcpp.so: Undefined symbol "backtrace_symbols"

It seems that the configure of Rcpp 1.1.1 does not find libexecinfo, which is a system library, and provides the backtrace library on FreeBSD system. So on the FreeBSD system, I have to install Rcpp 1.1.1 in R with

Sys.setenv("PKG_LIBS" = "-lexecinfo")
install.packages("Rcpp")

I also installed libbacktrace package, however, I could not make Rcpp to link the libbacktrace.so in /usr/local/lib

> sessionInfo()
R version 4.5.2 (2025-10-31)
Platform: amd64-portbld-freebsd15.0
Running under: FreeBSD pc 15.0-RELEASE-p1 FreeBSD 15.0-RELEASE-p1 releng/15.0-n280999-7bceec30b351 GENERIC amd64

Matrix products: default
LAPACK: /usr/local/lib/R/lib/libRlapack.so;  LAPACK version 3.12.1

locale:
[1] C.UTF-8/C.UTF-8/C.UTF-8/C/C.UTF-8/C.UTF-8

time zone: Asia/Chongqing
tzcode source: system (FreeBSD)

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] compiler_4.5.2

[eddelbuettel]

Thanks for the report. As I understand it, adding the linker flag -lexecinfo addresses your issue? We can look into that.

I however do not understand what you want to say in

I also installed libbacktrace package, however, I could not make Rcpp to link the libbacktrace.so in /usr/local/lib

Are you overlooking the fact that you may also have to alter configure.ac to actually look for the library?

[jszhao]

I however do not understand what you want to say in

I also installed libbacktrace package, however, I could not make Rcpp to link the libbacktrace.so in /usr/local/lib

Are you overlooking the fact that you may also have to alter configure.ac to actually look for the library?

I asked AI to analyze the error message, and it told me that Rcpp missed the libbacktrace library, so I installed libbacktrace package on FreeBSD, however, the error message appears again even I set LDFLAGS = -L/usr/local/lib -lbacktrace.

Frankly, I'd like Rcpp could find libexecinfo on FreeBSD, since it is provided by FreeBSD system. I, personally, do not like to alter any file of Rcpp itself, and do like to install addtional packages if it could be avoided.

[eddelbuettel]

Frankly, I'd like Rcpp could find libexecinfo on FreeBSD,

We can probably get there with your help.

For starters, if you grep for execinfo in our sources / in our repo you will see that we already have to special-case it for e.g. AIX. The main file is exceptions_impl.h and it responds to how RCPP_DEMANGLER_ENABLED is set which in turn is driven by whether execinfo.h is found.

So the question is: why does that fail on your end? We would need your help here as we do not have access to FreeBSD.

PS I could also be reading this wrong. Maybe it finds the header, but on FreeBSD then also needs another library? Again, we need your help in digging around on a FreeBSD system.

[jszhao]

The execinfo.h is in /usr/include, and libexecinfo.so is in /usr/lib. Since I am not familiar with C++ language, I don't know how to set up makefile, especially for Rcpp, to include the correct directories or find the specific library to link.

[eddelbuettel]

Good. So the header is found, and *BSD (or at least FreeBSD) is different in that we need an additional library added to PKG_LIBS. That should be doable. We not currently require a script configure but may now have to add one.

[eddelbuettel]

BTW do you already have a local file ~/.R/Makevars ? You could try adding it there in e.g.

SHLIB_LDFLAGS = -lexecinfo

(I use it to set strip flags for the linker and to turn lto on.)

[eddelbuettel]

Looks like xgboost does the test in configure.ac

AC_MSG_NOTICE([Checking if/where backtrace is available])
AC_CHECK_LIB([execinfo], [backtrace], [BACKTRACE_LIB=-lexecinfo], [BACKTRACE_LIB=''])
AS_IF([test -z "${BACKTRACE_LIB}"],
      dnl backtrace() might be unavailable (e.g., in musl libc)
      [AC_CHECK_FUNC(backtrace, [], [DMLC_DEFS="$DMLC_DEFS -DDMLC_LOG_STACK_TRACE=0"])])

[eddelbuettel]

Also: do you know if you have pkgconf (formerly pkg-config) installed? Does pkg --list-all | grep execinfo show something? If so, can you use the identified package in pkgconf --libs NAME_OF_PACKAGE_HERE to get -lexecinfo ? If so we could hook into that more easily and not require a full autoconf use.

[eddelbuettel]

So you identified a partial regression. On your system, ie on FreeBSD, the header is found, the functionality is made available ... and that then requires linking which we do not prepare for yet.

One possibility is to do something that picks up parts of the previous approach. You could try dropping this version of file excepctions_impl.h over yours at inst/include/Rcpp/exceptions_impl.h. Rcpp should then build. As it does with the addition of -lexecinfo to PKG_LIBS you already have.

[jszhao]

BTW do you already have a local file ~/.R/Makevars ? You could try adding it there in e.g.

SHLIB_LDFLAGS = -lexecinfo

(I use it to set strip flags for the linker and to turn lto on.)

I have a local file ~/.R/Makevars, and, SHLIB_LDFLAGS = -lexecinfo does not work. However, LDFLAGS = -lexecinfo or PKG_LIBS = -lexecinfo works.

Also: do you know if you have pkgconf (formerly pkg-config) installed? Does pkg --list-all | grep execinfo show something? If so, can you use the identified package in pkgconf --libs NAME_OF_PACKAGE_HERE to get -lexecinfo ? If so we could hook into that more easily and not require a full autoconf use.

I have pkgconf and pkg-config, however, pkg-config --list-all | grep execinfo does not return anything. On my system, i.e., FreeBSD 15.0, FreeBSD-libexecinfo-15.0 is the package name, and it is installed by the base system of FreeBSD.

[eddelbuettel]

Please also see my comment from an hour ago: if you could check whether it builds with the update exceptions_impl.h -- and with linking to -lexecinfo -- I would appreciate it.

[jszhao]

I clicked the link, and got Access to this site has been restricted.

Now, I recognized that it is in a branch named refine_demangler_setting. I will try it.

[eddelbuettel]

Yes I tried to help and linked to the 'raw mode' of the file; wget or curl can usually pull that. But that is the correct branch with an updated version.