Trying to build gcc cilk from sources following the instructions at https://www.cilkplus.org/download. This step repeatedly fails since the gnu.org git server is slow or something:

git clone http://gcc.gnu.org/git/gcc.git cilkplus-gcc 

Here's how to incrementally do a giant git clone from a slow server.

git init

git add .
git remote add cilkplus-gcc http://gcc.gnu.org/git/gcc.git
git pull http://gcc.gnu.org/git/gcc.git

It's painful, but with enough git pull operations, I seem to be able to get everything. Thanks to http://superuser.com/questions/154647/how-to-continue-cloning-a-git-repository-that-the-download-was-stopped

Note: the git add . gave an error, but I don't know if that meant it was a no-op.