Dear Git Maintainer, This bug is present in git from testing/backports.
# LANG=C apt policy git git: Installed: 1:2.17.1-1~bpo9+1 Candidate: 1:2.17.1-1~bpo9+1 Version table: *** 1:2.17.1-1~bpo9+1 500 500 http://ftp.pl.debian.org/debian stretch-backports/main amd64 Packages 100 /var/lib/dpkg/status 1:2.11.0-3+deb9u3 500 500 http://security.debian.org stretch/updates/main amd64 Packages 500 http://ftp.pl.debian.org/debian stretch-proposed-updates/main amd64 Packages 1:2.11.0-3+deb9u2 500 500 http://ftp.pl.debian.org/debian stretch/main amd64 Packages A script to reproduce: ----------------- #!/bin/bash git init foo cd foo touch bar git add -A git commit -mtest for i in .git/objects/*/*; do rm -f $i; mkdir $i; break; done git fsck # fatal: mmap failed: No such device ------------ Best Regards, Michał Mirosław