Unable to Build the Pens

[Sacolle]

Hi, i previously reported an issue with compilation of some user code. It ended being a result of some warning being promoted to errors in more recent versions of GCC. Right now, I'm attempting to compile the pens to visualize the generated .rsf data, but with no success.

How do I inject the include path and library path in the SCons build for it to recognize my libraries.

The OS of choice is NixOS, which makes things very reproducible, but for some reason the SCons configure step does not recognize the installed programs. My current attempt is to compile only the tiff pen, as a case study. The problem is that i do not know how SCons searches the system for environment variables in this step. More specifically, where does it load. For example, here follows the tiff code:

def tiff(context):
    context.Message("checking for tiff ... ")

    LIBS = path_get(context,'LIBS')

    text = '''
    #include <tiffio.h>
    int main(int argc,char* argv[]) {
    TIFF *tiffout;
    tiffout = TIFFOpen("test.tif","wb");
    return 0;
    }\n'''
    tiff = context.env.get('TIFF','tiff')
    LIBS.append(tiff)
    res = context.TryLink(text,'.c')

    if res:
        context.Result(res)
        context.env['TIFF'] = tiff
    else:
        context.Result(context_failure)
        context.env['TIFF'] = None
        stderr_write('sfbyte2tif, sftif2byte, and tiffpen will not be built.',
                     'bold')
        need_pkg('libtiff', fatal=False)

    LIBS.pop()

I'm not even sure if it finds the linker file, which i could point out in the config.py file (i think). The problem is that it doesn't even find the header files to include:

scons: Configure: checking for tiff ... 
.sconf_temp/conftest_27d86b58ca69c9cbb4cbb2835620d0a2_0.c <-
  |
  |    #include <tiffio.h>
  |    int main(int argc,char* argv[]) {
  |    TIFF *tiffout;
  |    tiffout = TIFFOpen("test.tif","wb");
  |    return 0;
  |    }
  |
gcc -o .sconf_temp/conftest_27d86b58ca69c9cbb4cbb2835620d0a2_0.o -c -O2 -x c -std=gnu17 -Wall -pedantic .sconf_temp/conftest_27d86b58ca69c9cbb4cbb2835620d0a2_0.c
.sconf_temp/conftest_27d86b58ca69c9cbb4cbb2835620d0a2_0.c:2:14: fatal error: tiffio.h: No such file or directory
    2 |     #include <tiffio.h>
      |              ^~~~~~~~~~
compilation terminated.

Which is strange. In the OS, when the libraries are present, it populates the variable NIX_CFLAGS_COMPILE with the flags of the included libs present in the environmente and then injects in the gcc compiler, which is not happening in the SCons build. The problem is that I simply do not know how to add it to the build, because adding it to CFLAGS, `CCFLAGS``, etc; does not change that compilation step.

$> echo $NIX_CFLAGS_COMPILE
-frandom-seed=kyc7aa8m13 -isystem /nix/store/iyff8129iampdw13nlfqalzhxy8y1hi9-python3-3.13.6/include -isystem /nix/store/wnlv4y888lggq0haibpwfzsl2vhlkciv-libtiff-4.7.0-dev/include -isystem /nix/store/iyff8129iampdw13nlfqalzhxy8y1hi9-python3-3.13.6/include -isystem /nix/store/wnlv4y888lggq0haibpwfzsl2vhlkciv-libtiff-4.7.0-dev/include

Simply put, where to add the specific path for the required program for compiling the pens?

I posted this question on the Nix forums to no avail. https://discourse.nixos.org/t/failing-to-recognize-package-built-with-scons/72920

So, how can i inject in the SCons build system for it to find my libraries and packages and build the pens?

[sfomel]

Thank you for your question. You can pass compiler flags to the Madagascar configure script as follows:

./configure CFLAGS=$NIX_CFLAGS_COMPILE

[Sacolle]

Thanks so much for the help. I was able to compile most of the pens and now i can use the package for my university project. Sadly i was not able to build the X11 pen. I think that is the last remaning pen. Achiving compilation of that pen would mean i could add the package to nixpkgs as a maintainer (if you'd like so), but also it could be left as a flake and be completelly usable in that way.

I think the issue with the X11 pens is this chunck in framework/configure.py.

INC = path_get(context,'XINC')
oldpath = path_get(context,'CPPPATH')

res = None
for path in [x for x in INC+xinc if os.path.isfile(os.path.join(x,'X11/Xaw/Label.h'))]:
    context.env['CPPPATH'] = oldpath + [path,]
    res = context.TryCompile(text,'.c')

    if res:
        context.Result(str(path))
        context.env['XINC'] = [path,]
        break

if not res:
    context.Result(context_failure)
    need_pkg('xaw', fatal=False)
    context.env['XINC'] = None
    return

It never outputs anything that compilation failed, only that it looked into the cache and failed to find.
I think the reason for that is that the for loop never finds the file in the precomputed paths. Is there a way for me to pass the folders to it via an environment vairable, like, does it read XINC like CFLAGS?

[sfomel]

Please make sure the libxaw package is installed. It may not come installed by default.

[Sacolle]

I have it installed in my setup, but in nix it saves to some folder like: /nix/store/bll3yl1pxqiyzhrpw26p493nninhc1bc-libXaw-1.0.16-dev/include, which is not on the search list:

xinc = [
    '/opt/X11/include',
    '/usr/X11/include',
    '/usr/X11R6/include',
    '/usr/X11R5/include',
    '/usr/X11R4/include',
    '/usr/include/X11',
    '/usr/include/X11R6',
    '/usr/include/X11R5',
    '/usr/include/X11R4',
    '/usr/local/X11/include',
    '/usr/local/X11R6/include',
    '/usr/local/X11R5/include',
    '/usr/local/X11R4/include',
    '/usr/local/include/X11',
    '/usr/local/include/X11R6',
    '/usr/local/include/X11R5',
    '/usr/local/include/X11R4',
    '/usr/X386/include',
    '/usr/x386/include',
    '/usr/XFree86/include/X11',
    '/usr/include',
    '/usr/local/include',
    '/opt/local/include',
    '/usr/unsupported/include',
    '/usr/athena/include',
    '/usr/local/x11r5/include',
    '/usr/lpp/Xamples/include',
    '/usr/openwin/include',
    '/usr/openwin/share/include'
    ]

So i'd need to pass it as an extra path to check. I just don't know how to do it. Do i call ./configure with ./configure XINC=/nix/store/bll3yl1pxqiyzhrpw26p493nninhc1bc-libXaw-1.0.16-dev/include ?