Похоже, что в репозитории битый пакет:
emerge -av dev-perl/Mouse
Local copy of remote index is up-to-date and will be used.
* IMPORTANT: 4 news items need reading for repository 'gentoo'.
* Use eselect news read to view new items.
These are the packages that would be merged, in order:
Calculating dependencies... done!
[binary N ] dev-perl/Mouse-2.4.10::gentoo USE="-examples -test" 116 KiB
Total: 1 package (1 new, 1 binary), Size of downloads: 116 KiB
Would you like to merge these packages? [Yes/No] yes
>>> Emerging binary (1 of 1) dev-perl/Mouse-2.4.10::gentoo
>>> Failed to emerge dev-perl/Mouse-2.4.10, Log file:
>>> '/var/calculate/tmp/portage/dev-perl/Mouse-2.4.10/temp/build.log'
>>> Jobs: 0 of 1 complete, 1 failed Load avg: 0.59, 0.41, 0.51
--2019-08-21 21:11:32-- https://mirror.yandex.ru/calculate/grp/x86_64/dev-perl/Mouse/Mouse-2.4.10-1.xpak
Resolving mirror.yandex.ru (mirror.yandex.ru)... 213.180.204.183, 2a02:6b8::183
Connecting to mirror.yandex.ru (mirror.yandex.ru)|213.180.204.183|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 118245 (115K) [application/octet-stream]
Saving to: ‘/var/calculate/packages/x86_64/dev-perl/Mouse-2.4.10.tbz2.partial’
0K .......... .......... .......... .......... .......... 43% 4.56M 0s
50K .......... .......... .......... .......... .......... 86% 5.92M 0s
100K .......... ..... 100% 113M=0.02s
2019-08-21 21:11:33 (5.90 MB/s) - ‘/var/calculate/packages/x86_64/dev-perl/Mouse-2.4.10.tbz2.partial’ saved [118245/118245]
!!! Digest verification failed:
!!! /var/calculate/packages/x86_64/dev-perl/Mouse-2.4.10.tbz2.partial
!!! Reason: Failed on size verification
!!! Got: 118245
!!! Expected: 118082
File renamed to '/var/calculate/packages/x86_64/dev-perl/Mouse-2.4.10.tbz2.partial._checksum_failure_.zsxex0zb'
Сделал несколько попыток - думал что сеть виновата, но результат тот же