git-clone fails when current user is not in /etc/passwd

My use case it running git clone inside a docker container with `docker run --user $(id -u):$(id -g) --volume /foo:/foo ...`. I want all /foo/* file creation/access from inside the Docker container to be done as the current uid/gid of the host system.

Steps to reproduce:

mkdir /tmp/docker-git cat > /tmp/docker-git/Dockerfile <<EOF FROM ubuntu RUN apt-get update && apt-get install -y git-core EOF docker build -t git /tmp/docker-git/ docker run --user $(id -u):$(id -g) git git clone https://github.com/git/git.git /tmp/git # fatal: unable to look up current user in the passwd file: no such user echo $? # 128

My current workaround is:

cat >> /tmp/docker-git/Dockerfile <<EOF RUN git config --system user.name Docker && git config --system user.email docker@localhost EOF

But I don't see why this should be necessary just to clone a repo. I run complex build jobs inside a docker container using this approach and git-clone is the first command to fail due to the lack of a passwd file entry for the current user. Some complain to stderr, but still succeed.

Regards, Taylor