CLI's version uses static str which prevents formatting

[cecton]

Original comment about the source of the issue: paritytech/cumulus#42 (comment)

In this particular case we want to add text in the description that shows how to use the command line to pass parameters to the relay chain and the para chain. To do that it would be best if we know the name of the executable.

Unfortunately Version takes static str so it is not possible to format at runtime.

cc @bkchr

[bkchr]

The problem I see is that everyone who implements a collator will need to replicate this piece of code. This should not be required.

[cecton]

We could/should use https://doc.rust-lang.org/std/env/fn.current_exe.html

But this is not possible because app_dirs requires &'static str.

I believe we can circumvent this issue by using lazy_static.

[pscott]

@cecton Has this issue been addressed? Trying to find the initial code, but github is giving me this error, and I can't find the code in the current repo...

It looks like it has been solved here:

https://github.com/paritytech/cumulus/blob/05a83e8bdbcf4c216e8632431aa49dd996ce4c3f/test/parachain/src/command.rs#L46-L51

but I'm not sure at all ^^

[cecton]

@pscott the stuff that was blocking to make it work is fixed (app_dirs). So it is now possible to convert all those &'static str to String instead AND to use current_exe instead of having to specify one.

To summarize:

1. If we convert the &'static str to String we can customize the description more easily
2. Having to specify the executable_name is a constraint introduced by the app_dirs dependency and it is less flexible (and more boilerplate) compared to using the current_exe()

You can pick the task if you want. I believe it should go without surprise but you can ping me if you have any issue.