Hi Karl,
On 1 June 2021 at 22:22, Karl Dunkle Werner wrote:
| I noticed the Makeconf file that comes with the Ubuntu version of R 4.1.0
| has link-time optimization (LTO) flags enabled. For instance:
| CXX11FLAGS = -g -O2 -ffile-prefix-map=/build/r-base-aXXzqd/r-base-4.1.0=.
| -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat
| -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -g $(LTO)
Upstream decision by R Core, see the NEWS entry:
LINK-TIME OPTIMIZATION on a UNIX-ALIKE:
* Configuring with flag --enable-lto=R now also uses LTO when
installing the recommended packages.
* R CMD INSTALL and R CMD SHLIB have a new flag --use-LTO to use
LTO when compiling code, for use with R configured with
--enable-lto=R. For R configured with --enable-lto, they have
the new flag --no-use-LTO.
Packages can opt in or out of LTO compilation _via_ a UseLTO
field in the DESCRIPTION file. (As usual this can be overridden
by the command-line flags.)
| If I understand things correctly, these flags cause a bit of a problem
| trying to install the arrow package, since that package does not want to
| override the CXX11FLAGS,
I doubt that, based on a wee bit of experience with C++, C++11, and all that
based coming up on 15 years with Rcpp, RInside and all that jazz.
| but also does not work with LTO. Setting "UseLTO:
| false" in the package description doesn't seem to work.
That is something you may need to discuss with either R Core upstream (for
the Makeconf), or maybe with the Arrow team for how they build the
package. And there could of course be a bug but I remind you that Arrow
itself is on CRAN.
| Would it be possible to remove the flags -flto=auto and -ffat-lto-objects?
Not likely for the package I ship. I tend to not second guess upstream, and
have followed R Core pretty much without changes to the program for 20 years.
If you think you need a locally modified version I may be able to help you
build one.
Hope this helps, Dirk
PS As for my experiences with Arrow, well. I will try to remain brief:
- while I have 25-ish years of experience building for Debian I _could
never_ build Arrow even as shipped for R; I did file (GitHub) bug reports
but they went nowhere (and I had no time for signing up for Jira, sorry)
- this included failure on the "rather unusual" second installation as the
Arrow build appears to not be entirely truthful by installing ... and then
not working telling you to reinstall
- that was generally on Ubuntu 'current at the time', but also on the Debian
testing machine I use for Rcpp reverse depends (and where I build well
over 2000 CRAN packages, yet Arrow remains "special")
- as of Arrow 4.0.0 I can at least succeed at the second stage
but I would be interested to hear how others fared on Debian or Ubuntu systems.
--
https://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org
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