What is libintl.h and where can I get it?

FWIW on OSX with El Capitan and homebrew, I did a:

1) I wasn't sure if the El Capitan upgrade had broken something, so first I made sure I had the latest gettext:

$ brew reinstall gettext

Then I had to re-link by doing:

$ brew unlink gettext && brew link gettext --force

After that, other tools were able to find it, and life went back to normal.

Depending on the system, it's probably part of the GNU C library (glibc).

Note that just installing the file libintl.h isn't likely to do you any good.

On Debian-based systems (including Debian, Ubuntu, and Linux Mint), it's part of the libc6-dev package, installed with:

sudo apt-get install libc6-dev

Since you're using Mac OS X, a Google search for "libintl.h OSX" shows a lot of people having similar problems. According to the INSTALL file in the Git sources:

Set NO_GETTEXT to disable localization support and make Git only use English. Under autoconf the configure script will do this automatically if it can't find libintl on the system.

I learned libintl comes from libgettext. If you already installed gettext by Homebrew, you would see:

$ locate libintl
/usr/local/Cellar/gettext/0.18.3.2/lib/libintl.8.dylib
/usr/local/Cellar/gettext/0.18.3.2/lib/libintl.a
/usr/local/Cellar/gettext/0.18.3.2/lib/libintl.dylib
<..snip..>

and the following works for me on the issue of "library not found for -lintl"

ln -s /usr/local/Cellar/gettext/0.18.3.2/lib/libintl.* /usr/local/lib/

If you can find the proper version of Libtools (from http://ftp.gnu.org/gnu/libtool/) you might find it in the package..

Otherwise you can use below to the configure to remove this dependency:

./configure --disable-nls