On Ubuntu 20.04, the `git TAB' will give me the following available subcommands: $ git TAB add deborig merge rm am describe mergetool send-email apply diff mv shortlog archive difftool notes show bisect fetch pull show-branch blame format-patch push sparse-checkout branch fsck range-diff stage bundle gc rebase stash checkout gitk reflog status cherry grep remote submodule cherry-pick gui repack switch citool help replace tag clean init request-pull whatchanged clone instaweb reset worktree commit latexdiff restore config log revert Then I try the following: $ git gui git: 'gui' is not a git command. See 'git --help'. The most similar commands are gc grep init pull push The git version is shown as below: $ git --version git version 2.25.1 As you can see, gui is among the auto-completed subcommands list, but it can be run like the manner of other subcommands. Any hints for this problem? Regards -- Assoc. Prof. Hongyi Zhao <hongyi.zhao@xxxxxxxxx> Theory and Simulation of Materials Hebei Polytechnic University of Science and Technology engineering NO. 552 North Gangtie Road, Xingtai, China