The compilation of conf-gmp.4 failed at "sh -exc cc -c $CFLAGS -I/usr/local/include test.c".

[Vinayakamk]

im trying in ubuntu,i tied to fix it,but i coudnt,plz help here

[jmid]

On Ubuntu conf-gmp should install libgmp-dev with your system package manager (apt on Ubuntu) and then try to compile an example test.c that depends on gmp.h.
You can find the opam file and the C-file here: https://github.com/ocaml/opam-repository/tree/master/packages/conf-gmp/conf-gmp.4

I'm guessing libgmp-dev is simply not installed on your machine.
So try to install it: sudo apt install libgmp-dev and then retry the opam install.

One explanation could be that you initially answered no when asked whether opam should be allowed to manage installation of system packages.