View source for gentoo perl upgrade slot conflict

 # '''emerge -uavND --quiet world'''
 <br>
 !!! Multiple package instances within a single package slot have been pulled
 !!! into the dependency graph, resulting in a slot conflict:

 dev-lang/perl:0

  (dev-lang/perl-5.26.9999:0/5.26::gentoo, ebuild scheduled for merge) pulled in by
    (no parents that aren't satisfied by other packages in this slot)

  (dev-lang/perl-5.24.3:0/5.24::gentoo, ebuild scheduled for merge) pulled in by
    dev-lang/perl:0/5.24=[-build(-)] required by (dev-perl/Authen-SASL-2.160.0-r1:0/0::gentoo, installed)
                 ^^^^^^^^                                                                                                                    
    (and 23 more with the same problem)


 # '''emerge -uavND -1 --nodeps dev-lang/perl'''
 These are the packages that would be merged, in order:
 [ebuild     U *] dev-lang/perl-5.26.9999:0/5.26::gentoo [5.24.1-r1:0/5.24::gentoo] USE="berkdb gdbm -debug -doc -ithreads" 11754 KiB
 Total: 1 package (1 upgrade), Size of downloads: 11754 KiB
 Would you like to merge these packages? [Yes/No] yes