You've currently -r1 stable, -r10 adds a bunch of patches from upstream that have gone without issues for long now. Please do your magic touches and stabilise mail-client/mutt-1.5.21-r10.
@grobian, please convert src_install to emake
amd64 stable
(In reply to comment #1) > @grobian, please convert src_install to emake done
x86 stable
Seems there are some bugs, please hold your horses. I'll revert for x86 and amd64.
See bug 421465 - the current stable mutt-r1 doesn't compile now (bug 420955). I requested stabilization of -r11 or -r12 before seeing this bugreport. Please decide on what needs to be done and notify the am-1.12 tracker.