This should be fixed in REQUIRED_USE.
fixed in ldns-1.7.0-r2
No, I think this is not fixed. "ssl" is still listed in USE, so one can still say USE="ecdsa" and get the same error. Additionally the error can be provoked also in ldns-utils, where the REQUIRED_USE constraints are also needed (for both dane and ecdsa!).
Thanks for spotting! I really forgot to finally remove ssl from USE. This is done now. We do not need the ssl USE flag here anymore because ldns does not build without ssl anymore so its mandatory and not an option. Does it work for you now? As for ldns-utils I added REQUIRED_USE in net-dns/ldns-utils-1.7.0-r1
Looks good now: USE='-dane -ecdsa -examples -gost -ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 USE='dane -ecdsa -examples -gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='-dane ecdsa examples -gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='dane ecdsa examples -gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='-dane -ecdsa -examples gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='dane -ecdsa -examples gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='dane ecdsa -examples gost -ssl' : REQUIRED_USE not satisfied (probably) for =net-dns/ldns-utils-1.7.0-r1 USE='dane -ecdsa -examples -gost ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 USE='-dane -ecdsa examples -gost ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 USE='-dane ecdsa -examples gost ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 USE='dane -ecdsa examples gost ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 USE='dane ecdsa examples gost ssl' succeeded for =net-dns/ldns-utils-1.7.0-r1 FEATURES= test succeeded for =net-dns/ldns-utils-1.7.0-r1