[Caml-list] Options -c and -o are incompatible when compiling C files

[Caml-list] Options -c and -o are incompatible when compiling C files

[Stéphane Glondu]

Hello,

kalzium (in Debian) fails to build with ocaml 4.05.0 because of the 
following error:
> [ 55%] Generating modwrap.o
> cd /tmp/kalzium-16.08.3/obj-x86_64-linux-gnu/src && /usr/bin/ocamlopt -I /usr/lib/ocaml/facile -c /tmp/kalzium-16.08.3/src/solver/modwrap.c -o /tmp/kalzium-16.08.3/obj-x86_64-linux-gnu/src/modwrap.o
> Options -c and -o are incompatible when compiling C files
> src/CMakeFiles/kalzium.dir/build.make:107: recipe for target 'src/modwrap.o' failed
> make[4]: *** [src/modwrap.o] Error 2
> make[4]: Leaving directory '/tmp/kalzium-16.08.3/obj-x86_64-linux-gnu'
> CMakeFiles/Makefile2:305: recipe for target 'src/CMakeFiles/kalzium.dir/all' failed
> make[3]: *** [src/CMakeFiles/kalzium.dir/all] Error 2

I am surprised by this error message: what is the rationale?

Investigating this, I bumped into:

   https://github.com/ocaml/ocaml/pull/761

Fabrice says: "In 4.04.0+beta1, ocamlc -c test.c -o subdir/test.o does 
not produce subdir/test.o but test.o.". But in ocaml 4.02.3, -c and -o 
used to work properly together (kalzium was building successfully). This 
looks like a regression to me.

-- 
Stéphane