How to tell MakeMaker to add exactly the libraries I want?

Question

I'm using XS to create a Perl Module which uses a C library.

For testing purposes, I've created a test library which has two simple functions:

void kzA()  (does a simple printf)
void kzB(int i, char *str) (does a printf of the received parameters)

I've also created some glue in XS, in order, for now, to access the kzA() function: (I'm only showing the function itself, but the includes are there, too, in the XS)

void
ka()
    CODE:
        printf("Before kzA()\n");
        kzA();
        printf("After kzA()\n");

So, I compiled the test library as fc.so, and it is in the same directory as my xs file, and my Makefile.PL (/workspace/LirePivots)

In my Makefile.PL, I set the LIBS key to ['-L/workspace/LirePivots -l:fc.so'], but when executing it with perl (perl Makefile.PL), it says "Warning (mostly harmless): No library found for -l:fc.so" It then writes a Makefile which does NOT mention said library. And then, after compiling (with "make") and installing (with "sudo make install"), when I run my test script which calls the ka() function from my module, I get the line "before", but the kzA() function isn't called, obviously, because it cannot find the kzA symbol, and the program stops there.

Creating a C test program which I would link with the very same arguments (-l:fc.so -L/workspace/LirePivots) does work, and, as long as I put the path in LD_LIBRARY_PATH, it finds the function and runs it correctly.

I also tried renaming the library libfc.so, and changing the -l part to "-lfc", but it didn't work either. It never manages to find the library.

Does anyone know what I do wrong ?

EDIT: As requested, I created a minimum example: https://github.com/kzwix/xsTest To run it, you'll need to have a Linux with Perl 5, along with XS (package perl-devel, on Redhat). And a C compiler, and make, obviously.

Answer 1

Ok, I still don't know the reason why it wouldn't find the library. But I found a workaround:

By adding the test library as "libfc.so" to /usr/lib, then running "sudo ldconfig", the library got added to the cache (when named fc.so, even if in /usr/lib, ldconfig would not add it. Also, it wouldn't work with symbolic links, either, I had to really copy it there).

After the library got added to the cache, "perl Makefile.PL" would still not find the library. I had to use "-L/usr/lib" in addition to "-lfc" for it to at long last find the library, and "agree" to add the parameters to the link step of the library.

After this happened, I could compile with "make", and executing the test program did work as originally intended (I saw both the "before" and "after" printf, and I saw the one from the function in the kzA() function from libfc.so)

Thanks Håkon Hægland for helping.

(I can't provide the Dockerfiles, they link to images internal to my organization, which I'm not allowed to share)