This is probably due to the floating dependencies without #148, but recent builds in a clean Go directory break with:
$ make test
go test -race ./...
? github.com/opencontainers/image-spec/cmd/oci-image-tool [no test files]
? github.com/opencontainers/image-spec/image [no test files]
--- FAIL: TestConfig (0.00s)
config_test.go:162: test 6: expected validation failure false but got true, err schema application/vnd.oci.image.serialization.config.v1+json: unable to validate: open /config-schema.json: no such file or directory
…