* guix/download.scm (url-fetch): Pass #:local-build? #t to 'build-expression->derivation'. * guix/git-download.scm (git-fetch): Likewise.
* guix/git-download.scm, guix/build/git.scm: New files. * Makefile.am (MODULES): Add them. * guix/packages.scm (<origin>): Fix comment for 'method' field.