I too was bitten by the portupgrade uninstall error, due to broken pipes, on my laptop running FreeBSD/amd64 stable/10. Others have identified the file 5.26 utility as the culprit, introduced in stable/10 as r298920. Watch PR 209211 for any progress. base/head was corrected at r299234, and stable/10 will follow soon.

Read More → portupgrade uninstall error, broken pipe