est/est_server_coap.c fails to compile when the configuration option --with-libcoap-dir is set:

[deviance]

$ make
[--snip--]
est_server_coap.c:2658:25: error: 'COAP_PKI_KEY_OSSL' undeclared (first
use in this function); did you mean 'COAP_PKI_KEY_ASN1'?
2658 | dtls_key.key_type = COAP_PKI_KEY_OSSL;