B0_ocaml: linking c libraries fails in some configurations

[saagraa]

Apologies in advance, I'm not certain if this a problem with B0 or something else.

In this repo (https://github.com/saagraa/ocaml_linking_example) I have a few makefiles and a B0.ml file:

• Makefile.b0 is in attempt to copy what B0 does
• Makefile and Makefile.2 swap the order of the -cclib parameters. They exclusively use -cclib, whereas the b0 one uses -ccopt
• Swapping the order of -cclib and -ccopt didn't impact the results in Makefile.b0.

I've got two systems:
System A:

• Ubuntu
• Linux 5.4
• gcc 9.4
• ld 2.34
• Ocaml 4.14.1 (ocamlopt -config-var native_c_libraries => -lm -ldl)

System B

• Void Linux
• Linux 4.4
• gcc 12.2
• ld 2.39
• Ocaml 4.14.1 (ocaml -config-var native_c_libraries => -lm)

On System A (older gcc/ld):

• make works and links main
• make -f Makefile.2 results in an ld error
• make -f Makefile.b0 results in an ld error
• b0 results in an ld error

On System B (newer gcc/ld):

• make works and links main
• make -f Makefile.2 works and links main
• make -f Makefile.b0 works and links main
• b0 works and links main

I'm guessing this is caused by some change from gcc 9.4 -> 12.2 and ld 2.34 -> 2.39. Nothing in the ld news file stands out to me though.