How to fix git credential manager core: git fatal: No credential backing store has been selected.

Problem:

After installing git credential manager core, you see this error message:

fatal: No credential backing store has been selected.

Set the GCM_CREDENTIAL_STORE environment variable or the credential.credentialStore Git configuration setting to one of the following options:

  secretservice : freedesktop.org Secret Service (requires graphical interface)
  gpg           : GNU `pass` compatible credential storage (requires GPG and `pass`)
  cache         : Git's in-memory credential cache
  plaintext     : store credentials in plain-text files (UNSECURE)

See https://aka.ms/gcmcore-linuxcredstores for more information.

Solution:

If you are on a graphical computer, run

git config --global credential.credentialStore secretservice

On a server, if automated i.e. passwordless access is required, use

git config --global credential.credentialStore plaintext

Note that this is insecure since all the passwords are stored in a plaintext file.