[working-directory: {{variable}}] doesn't seem to work

[jonathanunderwood]

Consider the following justfile:

mydir := "foo"

[working-directory: {{mydir}}]
recipe:
    echo Hello world

which, naively, I expected to work. But:

❯ just
error: Expected identifier or string, but found '{'
 ——▶ justfile:3:21
  │
3 │ [working-directory: {{mydir}}]
  │                     ^

So, perhaps this is expected to work (i.e. following the error message and providing an identifier:

mydir := "foo"

[working-directory: mydir]
recipe:
    echo Hello world

but:

❯ just
error: Expected keyword `x` but found identifier `mydir`
 ——▶ justfile:3:21
  │
3 │ [working-directory: mydir]
  │                     ^^^^^

So, I am not sure what the expected semantics of [working-directory: ...] are - the docs don't really tackle this.

[casey]

Unfortunately this isn't supported, see #2521 for the tracking issue.

[jonathanunderwood]

@casey thanks for the rapid response and clarifying this isn't yet expected to work at this time.

I do think there is an issue here as well with the incorrect error messages:

In the first case error: Expected identifier or string, but found '{' really shouldn't mention identifier, since, as you say, that's not currently supported.

In the second case error: Expected keyword xbut found identifiermydir`` is probably also wrong, since it doesn't seem that specifying x and hoping for shell expansion to work would lead to a good outcome.

[casey]

Ah yeah, that is confusing. The reason you get: Expected identifier or string, but found '{' is because a shell-expanded string, x"foo" is accepted, and x is an identifier. x is accepted though, for shell-expanded string, so Expected keyword x but found idntifier is a correct error message.

The just parser is only dimly aware of keywords, and mostly treats them like identifiers, so it might be hard to improve the error message, which should ideally be something like Expected x keyword or string, but found '{'.