Re: Custom pet projects compiling for NetBSD n00bs

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

On 08/01/2021 13:03, Lord Vader wrote:
> I'm trying to compile my pet C project under NetBSD (using 9.1 in i386 
> flavour).
>
> Specifically, I need libpng and libconfig. Both are installed using 
> pkg_add, both seem to have .so and includes under /usr/pkg path.
>
> Then, when I try to compile my code simply as gcc -c filename.c 
> filename.o, it fails at #include <png.h>.
> Further examination of gcc with `gcc -xc -E -v -` shows it doesn't have 
> default include path that point into /usr/pkg/include
> I managed to add them via -I or via CPATH env var, then I've managed to 
> do the same for linking via -L or LIBRARY_PATH, then I even got the 
> executable. Which again was unable to find .so under the /ust/pkg/lib , 
> unless I also use LD_LIBRARY_PATH for running it.
> I have experience with different linux distros, including ubuntu and 
> gentoo where everything seems to work off-the-box (provided I `apt 
> install` or `emerge` appropriate packages), but here I fail and probably 
> I do smth terribly wrong.
> Any suggestions?
That's because linux dumps everything in /usr/lib whereas only system 
libraries live there on NetBSD.

The linker option you need is -rpath=/usr/pkg/lib.

So you can do:

cc -o myprojects myfile.o -L/usr/pkg/lib -Wl,-rpath=/usr/pkg/lib -lpng 
-lconfig

You can specify a path in /etc/ld.so.conf but using rpath is how pkgsrc 
packages normally do this.

Mike