The GMP project uses Mercurial for its revision control. Mercurial is a distributed SCM, where your checkout is just another repository. Where the central repository lives is just an agreement between developers, not something Mercurial enforces.

hg clone https://gmplib.org/repo/gmp/ TARGDIR

hg clone https://gmplib.org/repo/gmp-6.0/ TARGDIR

for the current patch level of GMP 6.0.

A list of all repositories we publish are available at gmplib.org/repo/.

See also the Mercurial quickstart guide.

Once you have your own repository, you need to generate some build files. Perhaps the script .bootstrap works out-of-the box; if it doesn't, you need to install automake (at least version 1.11.6) and autoconf (at least version 2.59) and then try .bootstrap again. You may safely ignore the 4 lines of warnings from libtoolize.

Do not use autoreconf; it will overwrite config.guess which in turn will cause any builds to be awful.

Now you should be able to build GMP as usually, i.e., with

configure OPTIONS
make
make check