* build-aux/check-available-binaries.scm: Use 'derivation->output-path' instead of 'derivation-path->output-path'.
* build-aux/check-available-binaries.scm (%supported-systems): New variable. (native): Map over these.
* build-aux/check-available-binaries.scm: New file. * Makefile.am (EXTRA_DIST): Add it. (distcheck-hook, assert-binaries-available): New target.