Correction (Removing) the harmful line (if ${AVR_TARGET} is empty), as
-BUILDLINK_FNAME_TRANSFORM.avr-gcc+=    -e "s,${AVR_TARGET}/lib/,lib/,g"
(with comment, getting .builkdlink/lib/ -> .buildlinklib/ )

Looking for the resolution for packaging emulators/simulavr and
wip/simulavr-git (former has another problem now).