strongswan/swanctl config failing to load certs

certs-and-keys.log

$ find /usr/local/etc/swanctl/ -type f
/usr/local/etc/swanctl/x509/lb2Cert.der
/usr/local/etc/swanctl/rsa/lb2Key.der
/usr/local/etc/swanctl/swanctl.conf
/usr/local/etc/swanctl/x509ca/caCert.der

charon.log

00[LIB] loaded plugins: charon-systemd charon-systemd sha1 pem pkcs1 x509 revocation constraints pubkey random nonce kernel-netlink socket-default updown vici
00[JOB] spawning 16 worker threads
00[DMN] executing start script 'creds' (/usr/local/sbin/swanctl --load-creds)
00[DMN] executing start script 'conns' (/usr/local/sbin/swanctl --load-conns)
08[LIB] building CRED_CERTIFICATE - X509 failed, tried 3 builders
07[LIB] building CRED_CERTIFICATE - X509 failed, tried 3 builders
00[DMN] SIGTERM received, shutting down

strongswan.conf

# /usr/local/etc/strongswan.conf - strongSwan configuration file

swanctl {
  load = pem pkcs1 x509 revocation constraints pubkey openssl random 
}

charon {
  load = sha1 pem pkcs1 x509 revocation constraints pubkey openssl random nonce curl kernel-netlink socket-default updown vici

  fragment_size = 1400

  start-scripts {
    creds = /usr/local/sbin/swanctl --load-creds 
    conns = /usr/local/sbin/swanctl --load-conns
  }

  filelog {
    /var/log/charon.log {
      flush_line = yes
    }
  } 
}

swanctl.conf

# /usr/local/etc/swanctl/swanctl.conf
connections {
  pseudoprivate {
    # IKEv2 only
    version = 2
    # Allow fragmenting oversized payloads into multiple IPSEC packets
    fragmentation = yes
    # If a duplicate connection/SA is found, replace the existing one
    unique = replace
    # I think this is the set of ciphersuites available for IKE?
    proposals = aes128-sha256-modp3072

    mobike = no # cargo cult, no idea why this matters
    
    # do we need local_addrs and remote_addrs here, or is that handled
    # under children.<child>.local_ts and children.<child>.remote_ts?
    local_addrs = 172.16.0.0/24
    remote_addrs = 172.16.0.0/24
    
    # Describe how the local endpoint authenticates itself to remote
    # endpoints
    local {
      # List of X509 certs for authentication
      certs = lb2.der
      # "a private key associated to a usable certificate"
      # ^^^^ what??
      # This is not a path to a file, but a term that means "use a
      # key found <somewhere implied but not stated>"
      auth = pubkey
      
      # Arbitrary ID; must be unique among peers
      id = lb2
    }
    
    # Describe how remote endpoints should authenticate themselves
    remote {
      # accept only RSA 2048-bit or ECDSA 256-bit pubkeys for authN
      auth = rsa-2048-ecdsa-256
      cacerts = caCert.der
    }
    
    # Define parameters for "child" SAs to be negotiated once IKE
    # and auth are completed above
    children {
      pseudoprivatechild {
        # We shoudl trigger this child as soon as we detect matching traffic
        start_action = trap
        close_action = trap

        # ciphersuites for ESP once the SA is setup
        esp_proposals = aes128-sha256-modp3072
        # transport so we can still have broadcast traffic
        mode = transport
        
        # Include all traffic to/from 172.16.0.0/24
        local_ts = 172.16.0.0/24
        remote_ts = 172.16.0.0/24
        
        # Since this is within a datacenter, we should immediately
        # attempt to renegotiate when we detect a dead peer, to
        # avoid latency if/when the connection is eventually needed.
        dpd_action = restart
      }
    }
  }
}