[R-pkg-team] Bug#1064135: Help needed to pass -fsigned-char to r-cran-bigmemory

[Dirk Eddelbuettel]

On 12 May 2025 at 09:43, Charles Plessy wrote:
|   - A src/Makevars file containing +CXXFLAGS = -fsigned-char

a) maybe use += instead of = ?
b) maybe use PKG_CXXFLAGS instead as CXXFLAGS get overridden ?

b) should work but it's late-ish on a sunday eve here ...

This should be fixable. I'll try to take a look tomorrow afternoon if nobody
beats me to it...

|   - export DEB_CXXFLAGS_MAINT_APPEND = -fsigned-char in debian/rules
|   - Pass it directly through --configure-vars, with the following 
| debian/rules file:
| 
| -----------------------------------------------------------
| #!/usr/bin/make -f
| 
| CXXFLAGS := $(shell dpkg-buildflags --get CXXFLAGS) -fsigned-char
| 
| %:
|          dh $@ --buildsystem R
| 
| override_dh_auto_install:
|          mkdir -p ./debian/r-cran-bigmemory/usr/lib/R/site-library
|          R CMD INSTALL \
|                  --configure-vars='CXXFLAGS="$(CXXFLAGS)"' \
|                  -l ./debian/r-cran-bigmemory/usr/lib/R/site-library \
|                  --clean . \
|                  --built-timestamp='Wed, 17 Jan 2024 14:04:25 +0100'
| -----------------------------------------------------------
| 
| In none of these attempts I could see -fsigned-char in the build logs.
| 
| I am hitting a wall there as I have little knowledge about the use of 
| C/C++ in R packages.

There sadly are a few un(der)documented corners.
 
| Do you know how to pass compiler flags to R CMD INSTALL in the context 
| of dh $@ --buildsystem R ?

First step is to get it to work via 'R CMD INSTALL ...' and the Debian
wrapper come thereafter.

Cheers, Dirk

-- 
dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org