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

Calculating dependencies ...

!!! Problem resolving dependencies for =app-backup/dar-2.8.6
 done!
Dependency resolution took 0.85 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=app-backup/dar-2.8.6" has unmet requirements.
- app-backup/dar-2.8.6::gentoo USE="gpg nls xattr -argon2 -curl -dar32 -dar64 -doc -gcrypt -lz4 -lzo -rsync -sftp -whirlpool"

  The following REQUIRED_USE flag constraints are unsatisfied:
    gpg? ( gcrypt )

  The above constraints are a subset of the following complete expression:
    at-most-one-of ( dar32 dar64 ) gpg? ( gcrypt )