Compilation error with opam install integers.0.5.1

Hi, when I try to install integers.0.5.1 with opam I get this error:

/usr/lib/gcc/i586-mageia-linux-gnu/8.4.0/include/stdint.h:9:16: \
  fatal error: stdint.h: No such file or directory
# include_next <stdint.h>
$ ll /usr/lib/gcc/i586-mageia-linux-gnu/8.4.0/include/stdint.h
-rw-r--r-- 1 root root 328 Mar  4  2020 /usr/lib/gcc/i586-mageia-linux-gnu/8.4.0/include/stdint.h
$ ll /usr/include/stdint.h
-rw-r--r-- 1 root root 8.3K Jun 22  2021 /usr/include/stdint.h

Is there another -devel package I should install to provide another <stdint.h> header file?
The README of ocaml-integers don’t really say anything about it.

If I download the sources, and try to compile it, it compiles just fine.
So I tried to install the sources with: opam install . but opam pins this lib to version 0.5.1.
How can I remove the pin to install the sources instead?

opam install . should use the sources from the directory. Opam still needs a version number, so it takes the one declared in the opam file.

One exception to this: if you run opam pin or opam install from a version-controlled directory (e.g. a Git repository), changes that are not committed will not be considered, unless you use the --working-dir option.

Can you show opam pin list? Usually you should be able to remove outdated pins with opam pin remove <NAME>

It is possible that integers used to have some build issues but if the current sources compile it must’ve been fixed in the meantime. I looked at the changelog but didn’t find anything that would pinpoint to this issue, but might’ve been some small fix not mentioned in the log.