These are the packages that would be merged, in order:

Calculating dependencies ...

!!! Problem resolving dependencies for =net-p2p/bitcoin-core-31.0
 done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=net-p2p/bitcoin-core-31.0" has unmet requirements.
- net-p2p/bitcoin-core-31.0::gentoo USE="asm cli daemon dbus external-signer system-libsecp256k1 wallet -examples -gui -qrcode -systemtap -test -test-full -zeromq"

  The following REQUIRED_USE flag constraints are unsatisfied:
    dbus? ( gui )

  The above constraints are a subset of the following complete expression:
    dbus? ( gui ) qrcode? ( gui ) test-full? ( test )