[R-pkg-devel] set PKG_CONFIG_PATH before installing a package

[Travers Ching]

What Dirk said!  I'd also just add that it's useful to have a fallback
in case pkg-config fails, e.g., compile what you need from
source.  The configure script in RcppRedis looks like a good example of that.

Travers


Travers

On Mon, Apr 8, 2019 at 12:14 PM Dirk Eddelbuettel <edd using debian.org> wrote:
>
>
> On 8 April 2019 at 10:59, Travers Ching wrote:
> | I think the correct way to do it is through the configure script.  See
> | for example the Cairo package that uses pkg-config.  Configure scripts
> | are slightly hard to work through in my experience, but are worth it
> | if you need  customization of the installation environment.
>
> Or from the RcppRedis package you and I stand behind :)
>
> [...]
>
> ## ... but check for pkg-config
> AC_DEFUN([AC_PROG_PKGCONFIG], [AC_CHECK_PROG(PKGCONFIG,pkg-config,yes)])
> AC_PROG_PKGCONFIG
>
> ## use pkg-config for hiredis
> ##
> if test x"${PKGCONFIG}" == x"yes"; then
>     ## check via pkg-config for hiredis
>     if pkg-config --exists hiredis; then
>         ## obtain cflags and obtain libs
>         hiredis_cxxflags=`pkg-config --cflags hiredis`
>         hiredis_libs=`pkg-config --libs hiredis`
>         ## no need to build libhiredis.a
>         hiredis_tgt=""
>     else
>         AC_MSG_WARN([pkg-config exists but hiredis is not available.])
>     fi
> fi
>
> ## And make sure these flags are used for the tests below.
> CPPFLAGS="${hiredis_cxxflags} ${CPPFLAGS}"
> CXXFLAGS="${hiredis_cxxflags} ${CXXFLAGS}"
>
> [...]
>
> There is more at
>   https://github.com/eddelbuettel/rcppredis/blob/master/configure.ac
> but is a key part.
>
>
> Another useful trick is to just write a shell script 'configure' as one does
> not have to use 'autoconf' to produce 'configure' see eg
>   https://github.com/Rblp/Rblpapi/blob/master/configure
> for that approach, or one of Jeroen's packages.
>
>
> Last but not least you can call 'pkg-config' directly from src/Makevars too.
>
> Dirk
>
> --
> http://dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org