We've seen a recent issue with git checkout, where ever so often a git checkout fails due with the following error:

hudson.plugins.git.GitException: Command "git checkout -f bf2448efee1bfa57bcd6bfb06b63ca32e3c00de8" returned status code 128: stdout: stderr: fatal: unable to write new index file at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2681) at org.jenkinsci.plugins.gitclient.CliGitAPIImpl.access$1100(CliGitAPIImpl.java:86) at org.jenkinsci.plugins.gitclient.CliGitAPIImpl$9.execute(CliGitAPIImpl.java:2999)

This error seems flaky and only happens sometimes, but we've been seeing it a lot in our pipelines. Initially thought it was a space issue so checked the disk space for our agents as well as our Jenkins instance and saw that there was a lot of space left.