Using a use-based dep on a virtual isn't defined behavior and shouldn't be done. In this case, virtual/krb5[krb4] is used which is also an issue since app-crypt/heimdal, which also PROVIDEs virtual/krb5, doesn't have a krb4 use flag. Probably open-coding the packages that can work there is the easiest way to fix it up but there are other options as well.
> Probably open-coding the packages that can work there is the easiest way to fix > it up but there are other options as well. what does that mean ?
It means that putting app-crypt/mit-krb5[krb4] in there is probably what you want instead of using the virtual.
Fixed in evo and eds except eds-2.24.5-r2 which is going out of the tree as soon as 2.24.5-r3 is finished stabilizing. Thanks for reporting.