I am wondering how to cross build libgcc1 in a bootstrap setting. The obvious answer is "cross build gcc-4.9". Looking at its Build-Depends this means that I first need to build gmp to satisfy the dependency on libgmp-dev. Let us assume that this just works. Now libgmp-dev depends on libgmpxx4ldbl and libgmpxx4ldbl depends on libgcc1. Oops. We have a loop. So the obvious answer is wrong. What is the non-obvious answer? Helmut