[R-sig-Debian] LTO flags in 4.1.0 Ubuntu 21.04 Makeconf

[Dirk Eddelbuettel]

Hi Karl,

Thanks for circling back!

On 4 June 2021 at 17:00, Karl Dunkle Werner wrote:
| For anyone else who runs into this issue, you can do either of the 
| following;
| (a) Remove the flags "-flto=auto" and "-ffat-lto-objects" from the 
| CXX11FLAGS in your /etc/R/Makeconf
| (b) Set CXX11FLAGS in your Makevars (in $HOME/.R/Makevars) to something 
| like the following:
| 
| CXX11FLAGS = -g -O2 -ffile-prefix-map=/build/r-base-aXXzqd/r-base-4.1.0=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -g
| 
| (This is just the Makeconf CXX11FLAGS with LTO flags removed).
| Note that these may turn off LTO for other packages you install, 
| depending on how they manage build flags.

Thanks for the concise summary.

The other side of all this is that you reminded me that I should probably
enable lto as a default. I may need to reach out with some testing help.

Best, Dirk 

-- 
https://dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org