newbie compile question. please help

Dear Folks,

Could someone please tell what I am doing wrong?

I made some minor changes to

main.c then

make then

make install

when I want to start the postmaster I get

The program "postmaster" was found by
"/home/gevik/postgres/build2/bin/pg_ctl"

but was not the same version as pg_ctl.

Check your installation.

What am I doing wrong here?

Regards,

Gevik