Hello @clin.1 ,
gc-nano libraries should be installed and deployed following the different Starter/Developer/Distribution package provided on the wiki by ST.
If you modified or removed things on your target, I advice you to restart from a clean environment following the different wiki articles, depending on your way to work.
If you want to just recompile / modify the different components such as Kernel, U-Boot... follow this article.
If you want to compile the entire OSTL distribution and modify it as you want, follow this article.