This script converts lightweight tags migrated from Subversion to annotated tags. It also moves the tag to it parent commit which is identical to itself. This makes the git describe works as expected.

to_annotated_tag.sh

#!/bin/bash

echo "Convert lightweight tag to annotated tag..."
for tg in $(git tag |grep REL)
do
    newtag=${tg#REL_}
    newtag=${newtag//_/.}
    cmt=$(git log -1 --pretty=%s $tg)
    tagger=$(git log -1 --pretty=%an $tg)
    tagmail=$(git log -1 --pretty=%ae $tg)
    tagdate=$(git log -1 --pretty=%ad $tg)
    export GIT_COMMITTER_EMAIL=$tagmail
    export GIT_COMMITTER_DATE=$tagdate
    export GIT_COMMITTER_NAME=$tagger

    dff=$(git diff $tg^ $tg)
    if [[ -z $dff ]]
    then
        git tag -a -m "$cmt" $newtag $tg^
    else
        git tag -a -m "$cmt" $newtag $tg
    fi
    git tag -d $tg
done

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