Changing PS1 just so is somewhat risky, but vcsh sets $VCSH_REPO_NAME for precisely this reason; I use it in my own shell, as well. Maybe we should make that clearer in the docs?

Like Richard said, a command line tool manipulating the parent shell is kind of a minefield situation and it would not be appropriate for VCSH to do this and at the same time expect the user's regular shell to work. The only way we could handle this more directly is with a REPL interface that doesn't claim to be a full shell following the user's other preferences.

Also like he said $VCSH_REPO_NAME and other environment variables are set just for this use. You can configure your existing shell prompt to alert you if you are in a VCSH repo. For example my own shell (Zsh with prezto using the Powerline10k theme) sets it up like this:

typeset -g POWERLEVEL9K_CUSTOM_VCSH=zsh_vcsh
typeset -g POWERLEVEL9K_CUSTOM_VCSH_BACKGROUND='202'
typeset -g POWERLEVEL9K_CUSTOM_VCSH_FOREGROUND='234'
zsh_vcsh () {
	echo -n ${VCSH_REPO_NAME}
}
typeset -g POWERLEVEL9K_LEFT_PROMPT_ELEMENTS=(root_indicator user host dir custom_vcsh vcs)

The resulting shell prompt before and after entering a VCSH repo looks like this:

Another thing to mention if it interests you is that the next version of starship (v0.52.0) will include out of the box support for showing VCSH information. You can use the Git HEAD version now or check it out after the next release. Support was contributed here.

Some sample configs for various shells in the docs would probably be a good plan.

Thank you @RichiH and @alerque for your fast reply, I'd totally agree with your observation: the usage of variable VCSH_REPO_NAME would be more than enough and safer.

From my point of view it could be helpful to highlight such usage into the docs.

The idea of updating the PS1 was stolen from virtualenv, but I agree that - safety apart - sometimes it is also really annoying especially when it messes with the console layout.

I understand this issue might be resolved for you, but lets keep the issue open to track getting this end of things better documented for other first time users. If it's noisy for you you can unsubscribe from notifications to this issue from the sidebar.

Out of the box support for VCSH info in the prompt shipped in Starship v0.52.1.