git - Find the commit that changed file permissions -

what combination of arguments git log or similar find commit changed permissions on file?

i can use git log -p <file> , grep "new mode", doesn't seem satisfying.

my solution use git log --summary , grep

list commits permission of given file modified

git log --summary {file} |grep -e ^commit -e"=>"|grep '=>' -b1 | grep ^commit 

if {file} omitted, list commits, file's permission modified.