Does not work with 'set -o nounset' because of undefined variables usage

[cyril-bouthors]

Liquidprompt does not work when enabling the BASH 'nounset' feature, each prompt shows the three following warnings:

09:08:57 θ81° [cyb@home:~] $ set -o nounset
-bash: ret: unbound variable
-bash: LP_TIME_ANALOG: unbound variable
-bash: http_proxy: unbound variable
09:09:02 θ81° [cyb@home:~] $ 

Would it be possible to make sure variables are defined before using them?

[dolmen]

For reference (at least for myself), here is the relevant part of the bash manual about nounset:

Treat unset variables and parameters other than the special parameters "@" and "*" as an error when performing parameter expansion. If expansion is attempted on an unset variable or parameter, the shell prints an error message, and, if not interactive, exits with a non-zero status.

About your question, I think it would be a big effort (if even possible) to make liquidprompt clean for nounset. Note that would require testing with nounset not just the runtime, but also checking the initial loading of liquidprompt (that currently raises more errors).

I don't intend to spend my own time resources on this effort, but patches are welcome!

Note that on Ubuntu, filename completion seems to have issues working with nounset, so just fixing liquidprompt would not be enough for a clean user experience with nounset.

[dolmen]

Related: #360 (fixed by #361).

[dolmen]

bash-completion (which is something most liquidprompt+bash users will use, as I do myself) is not yet nounset-safe. This is on bash-completion roadmap for 3.0.

Anyway, I have some work in progress for liquidprompt in the fix/usage-of-undef-variables branch...

[dolmen]

I've fixed all cases I found so far with a8114dd.

[Rycieos]

I have both manually inspected the source for set -u errors as well as tested thoroughly. This is now greatly improved in v2.0.0-beta.1.

However, as dolmen noted in #354 (comment), bash-completion still does not support set -u, so I can't run set -u on my daily driver shells. There might still be some edge case I failed to catch. Please open a new issue if you find one.