void repo_search(Repo *repo, Id p, Id key, const char *match, int flags, int (*callback)(void *cbdata, Solvable *s, Repodata *data, Repokey *key, KeyValue *kv), void *cbdata);
/* returns the string value of the attribute, or NULL if not found */
void repo_search(Repo *repo, Id p, Id key, const char *match, int flags, int (*callback)(void *cbdata, Solvable *s, Repodata *data, Repokey *key, KeyValue *kv), void *cbdata);
/* returns the string value of the attribute, or NULL if not found */